1 00:00:00,000 --> 00:00:00,490 2 00:00:00,490 --> 00:00:03,839 In this video, I want to do a bunch of examples involving 3 00:00:03,839 --> 00:00:05,200 exponent properties. 4 00:00:05,200 --> 00:00:07,860 But, before I even do that, let's have a little bit of a 5 00:00:07,860 --> 00:00:10,970 review of what an exponent even is. 6 00:00:10,970 --> 00:00:15,380 So let's say I had 2 to the third power. 7 00:00:15,380 --> 00:00:17,630 You might be tempted to say, oh is that 6? 8 00:00:17,629 --> 00:00:20,009 And I would say no, it is not 6. 9 00:00:20,010 --> 00:00:23,580 This means 2 times itself, three times. 10 00:00:23,579 --> 00:00:29,939 So this is going to be equal to 2 times 2 times 2, which is 11 00:00:29,940 --> 00:00:32,548 equal to 2 times 2 is 4. 12 00:00:32,548 --> 00:00:35,219 4 times 2 is equal to 8. 13 00:00:35,219 --> 00:00:40,089 If I were to ask you what 3 to the second power is, or 3 14 00:00:40,090 --> 00:00:45,109 squared, this is equal to 3 times itself two times. 15 00:00:45,109 --> 00:00:48,219 This is equal to 3 times 3. 16 00:00:48,219 --> 00:00:50,030 Which is equal to 9. 17 00:00:50,030 --> 00:00:51,060 Let's do one more of these. 18 00:00:51,060 --> 00:00:54,080 I think you're getting the general sense, if you've never 19 00:00:54,079 --> 00:00:56,079 seen these before. 20 00:00:56,079 --> 00:01:03,019 Let's say I have 5 to the seventh power. 21 00:01:03,020 --> 00:01:07,120 That's equal to 5 times itself, seven times. 22 00:01:07,120 --> 00:01:16,280 5 times 5 times 5 times 5 times 5 times 5 times 5. 23 00:01:16,280 --> 00:01:16,960 That's seven, right? 24 00:01:16,959 --> 00:01:19,199 One, two, three, four, five, six, seven. 25 00:01:19,200 --> 00:01:21,560 This is going to be a really, really, really, really, large 26 00:01:21,560 --> 00:01:23,710 number and I'm not going to calculate it right now. 27 00:01:23,709 --> 00:01:26,469 If you want to do it by hand, feel free to do so. 28 00:01:26,469 --> 00:01:28,620 Or use a calculator, but this is a really, really, really, 29 00:01:28,620 --> 00:01:29,320 large number. 30 00:01:29,319 --> 00:01:32,399 So one thing that you might appreciate very quickly is 31 00:01:32,400 --> 00:01:35,000 that exponents increase very rapidly. 32 00:01:35,000 --> 00:01:39,700 5 to the 17th would be even a way, way more massive number. 33 00:01:39,700 --> 00:01:41,920 But anyway, that's a review of exponents. 34 00:01:41,920 --> 00:01:47,129 Let's get a little bit steeped in algebra, using exponents. 35 00:01:47,129 --> 00:01:52,609 So what would 3x-- let me do this in a different color-- 36 00:01:52,609 --> 00:01:59,670 what would 3x times 3x times 3x be? 37 00:01:59,670 --> 00:02:02,340 Well, one thing you need to remember about multiplication 38 00:02:02,340 --> 00:02:04,990 is, it doesn't matter what order you do the 39 00:02:04,989 --> 00:02:06,059 multiplication in. 40 00:02:06,060 --> 00:02:10,439 So this is going to be the same thing as 3 times 3 times 41 00:02:10,439 --> 00:02:16,550 3 times x times x times x. 42 00:02:16,550 --> 00:02:20,620 And just based on what we reviewed just here, that part 43 00:02:20,620 --> 00:02:24,159 right there, 3 times 3, three times, that's 3 44 00:02:24,159 --> 00:02:25,780 to the third power. 45 00:02:25,780 --> 00:02:30,210 And this right here, x times itself three times. 46 00:02:30,210 --> 00:02:32,750 that's x to the third power. 47 00:02:32,750 --> 00:02:36,050 So this whole thing can be rewritten as 3 to the third 48 00:02:36,050 --> 00:02:37,570 times x to the third. 49 00:02:37,569 --> 00:02:40,959 Or if you know what 3 to the third is, this is 9 times 3, 50 00:02:40,960 --> 00:02:42,240 which is 27. 51 00:02:42,240 --> 00:02:46,180 This is 27 x to the third power. 52 00:02:46,180 --> 00:02:49,840 Now you might have said, hey, wasn't 3x times 3x times 3x. 53 00:02:49,840 --> 00:02:52,830 Wasn't that 3x to the third power? 54 00:02:52,830 --> 00:02:53,140 Right? 55 00:02:53,139 --> 00:02:55,479 You're multiplying 3x times itself three times. 56 00:02:55,479 --> 00:02:57,560 And I would say, yes it is. 57 00:02:57,560 --> 00:03:03,210 So this, right here, you could interpret that as 3x to the 58 00:03:03,210 --> 00:03:04,730 third power. 59 00:03:04,729 --> 00:03:06,949 And just like that, we stumbled on one of our 60 00:03:06,949 --> 00:03:08,280 exponent properties. 61 00:03:08,280 --> 00:03:09,289 Notice this. 62 00:03:09,289 --> 00:03:11,599 When I have something times something, and the whole thing 63 00:03:11,599 --> 00:03:15,430 is to the third power, that equals each of those things to 64 00:03:15,430 --> 00:03:17,490 the third power times each other. 65 00:03:17,490 --> 00:03:21,290 So 3x to the third is the same thing is 3 to the third times 66 00:03:21,289 --> 00:03:27,859 x to the third, which is 27 to the third power. 67 00:03:27,860 --> 00:03:30,730 Let's do a couple more examples. 68 00:03:30,729 --> 00:03:39,049 What if I were to ask you what 6 to the third times 6 to the 69 00:03:39,050 --> 00:03:40,410 sixth power is? 70 00:03:40,409 --> 00:03:42,859 And this is going to be a really huge number, but I want 71 00:03:42,860 --> 00:03:45,480 to write it as a power of 6. 72 00:03:45,479 --> 00:03:50,289 Let me write the 6 to the sixth in a different color. 73 00:03:50,289 --> 00:03:53,459 6 to the third times 6 to the sixth power, what is this 74 00:03:53,460 --> 00:03:55,540 going to be equal to? 75 00:03:55,539 --> 00:03:58,199 Well, 6 to the third, we know that's 6 times 76 00:03:58,199 --> 00:03:59,879 itself three times. 77 00:03:59,879 --> 00:04:03,400 So it's 6 times 6 times 6. 78 00:04:03,400 --> 00:04:07,439 And then that's going to be times-- the times here is in 79 00:04:07,439 --> 00:04:09,060 green, so I'll do it in green. 80 00:04:09,060 --> 00:04:11,430 Maybe I'll make both of them in orange. 81 00:04:11,430 --> 00:04:15,990 That is going to be times 6 to the sixth power. 82 00:04:15,990 --> 00:04:17,430 Well, what's 6 to the sixth power? 83 00:04:17,430 --> 00:04:20,540 That's 6 times itself six times. 84 00:04:20,540 --> 00:04:27,180 So, it's 6 times 6 times 6 times 6 times 6. 85 00:04:27,180 --> 00:04:29,379 Then you get one more, times 6. 86 00:04:29,379 --> 00:04:31,620 So what is this whole number going to be? 87 00:04:31,620 --> 00:04:34,740 Well, this whole thing-- we're multiplying 6 times itself-- 88 00:04:34,740 --> 00:04:35,560 how many times? 89 00:04:35,560 --> 00:04:38,649 One, two, three, four, five, six, seven, 90 00:04:38,649 --> 00:04:40,639 eight, nine times, right? 91 00:04:40,639 --> 00:04:44,449 Three times here and then another six times here. 92 00:04:44,449 --> 00:04:47,449 So we're multiplying 6 times itself nine times. 93 00:04:47,449 --> 00:04:48,909 3 plus 6. 94 00:04:48,910 --> 00:04:55,360 So this is equal to 6 to the 3 plus 6 power or 6 95 00:04:55,360 --> 00:04:57,100 to the ninth power. 96 00:04:57,100 --> 00:04:58,650 And just like that, we/ve stumbled on 97 00:04:58,649 --> 00:05:01,129 another exponent property. 98 00:05:01,129 --> 00:05:04,100 When we take exponents, in this case, 6 to the third, the 99 00:05:04,100 --> 00:05:05,760 number 6 is the base. 100 00:05:05,759 --> 00:05:09,189 We're taking the base to the exponent of 3. 101 00:05:09,189 --> 00:05:11,899 When you have the same base, and you're multiplying two 102 00:05:11,899 --> 00:05:17,359 exponents with the same base, you can add the exponents. 103 00:05:17,360 --> 00:05:19,850 Let me do several more examples of this. 104 00:05:19,850 --> 00:05:23,020 Let's do it in magenta. 105 00:05:23,019 --> 00:05:29,419 Let's say I had 2 squared times 2 to the fourth times 2 106 00:05:29,420 --> 00:05:31,030 to the sixth. 107 00:05:31,029 --> 00:05:33,839 Well, I have the same base in all of these, so 108 00:05:33,839 --> 00:05:35,339 I can add the exponents. 109 00:05:35,339 --> 00:05:41,489 This is going to be equal to 2 to the 2 plus 4 plus 6, which 110 00:05:41,490 --> 00:05:44,970 is equal to 2 to the 12th power. 111 00:05:44,970 --> 00:05:46,680 And hopefully that makes sense, because this is going 112 00:05:46,680 --> 00:05:51,439 to be 2 times itself two times, 2 times itself four 113 00:05:51,439 --> 00:05:53,879 times, 2 times itself six times. 114 00:05:53,879 --> 00:05:56,000 When you multiply them all out, it's going to be 2 times 115 00:05:56,000 --> 00:06:00,350 itself, 12 times or 2 to the 12th power. 116 00:06:00,350 --> 00:06:04,740 Let's do it in a little bit more abstract way, using some 117 00:06:04,740 --> 00:06:08,150 variables, but it's the same exact idea. 118 00:06:08,149 --> 00:06:14,569 What is x to the squared or x squared times x to the fourth? 119 00:06:14,569 --> 00:06:16,610 Well, we could use the property we just learned. 120 00:06:16,610 --> 00:06:19,060 We have the exact same base, x. 121 00:06:19,060 --> 00:06:22,300 So it's going to be x to the 2 plus 4 power. 122 00:06:22,300 --> 00:06:25,100 It's going to be x to the sixth power. 123 00:06:25,100 --> 00:06:29,379 And if you don't believe me, what is x squared? 124 00:06:29,379 --> 00:06:33,209 x squared is equal to x times x. 125 00:06:33,209 --> 00:06:37,109 And if you were going to multiply that times x to the 126 00:06:37,110 --> 00:06:41,629 fourth, you're multiplying it by x times itself four times. 127 00:06:41,629 --> 00:06:46,199 x times x times x times x. 128 00:06:46,199 --> 00:06:49,560 So how many times are you now multiplying x by itself? 129 00:06:49,560 --> 00:06:53,470 Well, one, two, three, four, five, six times. 130 00:06:53,470 --> 00:06:56,280 x to the sixth power. 131 00:06:56,279 --> 00:06:58,469 Let's do another one of these. 132 00:06:58,470 --> 00:07:02,280 The more examples you see, I figure, the better. 133 00:07:02,279 --> 00:07:05,759 So let's do the other property, just to 134 00:07:05,759 --> 00:07:06,589 mix and match it. 135 00:07:06,589 --> 00:07:14,319 Let's say I have a to the third to the fourth power. 136 00:07:14,319 --> 00:07:16,610 So I'll tell you the property here, and I'll show you why it 137 00:07:16,610 --> 00:07:17,449 makes sense. 138 00:07:17,449 --> 00:07:19,879 When you add something to an exponent, and then you raise 139 00:07:19,879 --> 00:07:22,680 that to an exponent, you can multiply the exponents. 140 00:07:22,680 --> 00:07:28,160 So this is going to be a to the 3 times 4 power or a to 141 00:07:28,160 --> 00:07:30,020 the 12th power. 142 00:07:30,019 --> 00:07:31,729 And why does that make sense? 143 00:07:31,730 --> 00:07:35,340 Well this right here is a to the third 144 00:07:35,339 --> 00:07:36,819 times itself four times. 145 00:07:36,819 --> 00:07:41,329 So this is equal to a to the third times a to the third 146 00:07:41,329 --> 00:07:45,300 times a to the third times a to the third. 147 00:07:45,300 --> 00:07:48,430 Well, we have the same base, so we can add the exponents. 148 00:07:48,430 --> 00:07:52,620 So there's going to be a to the 3 times 4, right? 149 00:07:52,620 --> 00:07:57,910 This is equal to a to the 3 plus 33 plus three plus 3 150 00:07:57,910 --> 00:08:03,600 power, which is the same thing is a the 3 times 4 power or a 151 00:08:03,600 --> 00:08:05,010 to the 12th power. 152 00:08:05,009 --> 00:08:07,579 So just to review the properties we've learned so 153 00:08:07,579 --> 00:08:11,560 far in this video, besides just a review of what an 154 00:08:11,560 --> 00:08:19,829 exponent is, if I have x to the a power times x to the b 155 00:08:19,829 --> 00:08:22,550 power, this is going to be equal to x to 156 00:08:22,550 --> 00:08:25,120 the a plus b power. 157 00:08:25,120 --> 00:08:27,949 We saw that right here. 158 00:08:27,949 --> 00:08:30,615 x squared times x to the fourth is equal to x to the 159 00:08:30,615 --> 00:08:32,490 sixth, 2 plus 4. 160 00:08:32,490 --> 00:08:39,500 We also saw that if I have x times y to the a power, this 161 00:08:39,500 --> 00:08:42,440 is the same thing is x to the a power 162 00:08:42,440 --> 00:08:44,680 times y to the a power. 163 00:08:44,679 --> 00:08:46,809 We saw that early on in this video. 164 00:08:46,809 --> 00:08:49,569 We saw that over here. 165 00:08:49,570 --> 00:08:53,000 3x to the third is the same thing as 3 to the third times 166 00:08:53,000 --> 00:08:55,129 x to the third. 167 00:08:55,129 --> 00:08:56,409 That's what this is saying right here. 168 00:08:56,409 --> 00:09:00,459 3x to the third is the same thing is 3 to the third times 169 00:09:00,460 --> 00:09:01,730 x to the third. 170 00:09:01,730 --> 00:09:05,720 And then the last property, which we just stumbled upon 171 00:09:05,720 --> 00:09:10,710 is, if you have x to the a and then you raise that to the bth 172 00:09:10,710 --> 00:09:15,430 power, that's equal to x to the a times b. 173 00:09:15,429 --> 00:09:18,459 And we saw that right there. a to the third and then raise 174 00:09:18,460 --> 00:09:21,690 that to the fourth power is the same thing is a to the 3 175 00:09:21,690 --> 00:09:25,280 times 4 or a to the 12th power. 176 00:09:25,279 --> 00:09:32,970 So let's use these properties to do a handful of more 177 00:09:32,970 --> 00:09:48,070 complex problems. Let's say we have 2xy squared times 178 00:09:48,070 --> 00:09:55,060 negative x squared y squared times 179 00:09:55,059 --> 00:09:57,899 three x squared y squared. 180 00:09:57,899 --> 00:09:59,329 And we wanted to simplify this. 181 00:09:59,330 --> 00:10:04,980 182 00:10:04,980 --> 00:10:07,550 This you can view as negative 1 times x 183 00:10:07,549 --> 00:10:08,929 squared times y squared. 184 00:10:08,929 --> 00:10:13,349 So if we take this whole thing to the squared power, this is 185 00:10:13,350 --> 00:10:15,670 like raising each of these to the second power. 186 00:10:15,669 --> 00:10:19,589 So this part right here could be simplified as negative 1 187 00:10:19,590 --> 00:10:26,320 squared times x squared squared, times y squared. 188 00:10:26,320 --> 00:10:28,270 And then if we were to simplify that, negative 1 189 00:10:28,269 --> 00:10:31,889 squared is just 1, x squared squared-- remember you can 190 00:10:31,889 --> 00:10:35,100 just multiply the exponents-- so that's going to be x to the 191 00:10:35,100 --> 00:10:37,769 fourth y squared. 192 00:10:37,769 --> 00:10:40,345 That's what this middle part simplifies to. 193 00:10:40,345 --> 00:10:43,759 And let's see if we can merge it with the other parts. 194 00:10:43,759 --> 00:10:47,409 The other parts, just to remember, were 2 xy squared, 195 00:10:47,409 --> 00:10:51,350 and then 3x squared y squared. 196 00:10:51,350 --> 00:10:53,379 Well now we're just going ahead and just straight up 197 00:10:53,379 --> 00:10:54,399 multiplying everything. 198 00:10:54,399 --> 00:10:56,709 And we learned in multiplication that it doesn't 199 00:10:56,710 --> 00:10:58,860 matter which order you multiply things in. 200 00:10:58,860 --> 00:10:59,930 So I can just rearrange. 201 00:10:59,929 --> 00:11:02,149 We're just going and multiplying 2 times x times y 202 00:11:02,149 --> 00:11:04,600 squared times x to the fourth times y squared times 3 times 203 00:11:04,600 --> 00:11:05,550 x squared times y squared. 204 00:11:05,549 --> 00:11:10,289 So I can rearrange this, and I will rearrange it so that it's 205 00:11:10,289 --> 00:11:11,799 in a way that's easy to simplify. 206 00:11:11,799 --> 00:11:16,995 So I can multiply 2 times 3, and then I can worry about the 207 00:11:16,995 --> 00:11:18,610 x terms. 208 00:11:18,610 --> 00:11:19,960 Let me do it in this color. 209 00:11:19,960 --> 00:11:30,330 Then I have times x times x to the fourth times x squared. 210 00:11:30,330 --> 00:11:36,080 And then I have to worry about the y terms, times y squared 211 00:11:36,080 --> 00:11:40,036 times another y squared times another y squared. 212 00:11:40,035 --> 00:11:42,949 213 00:11:42,950 --> 00:11:44,600 And now what are these equal to? 214 00:11:44,600 --> 00:11:45,879 Well, 2 times 3. 215 00:11:45,879 --> 00:11:47,200 You knew how to do that. 216 00:11:47,200 --> 00:11:49,330 That's equal to 6. 217 00:11:49,330 --> 00:11:53,450 And what is x times x to the fourth times x squared. 218 00:11:53,450 --> 00:11:56,310 Well, one thing to remember is x is the same thing as x to 219 00:11:56,309 --> 00:11:57,339 the first power. 220 00:11:57,340 --> 00:12:00,480 Anything to the first power is just that number. 221 00:12:00,480 --> 00:12:03,129 So you know, 2 to the first power is just 2. 222 00:12:03,129 --> 00:12:05,970 3 to the first power is just 3. 223 00:12:05,970 --> 00:12:08,779 So what is this going to be equal to? 224 00:12:08,779 --> 00:12:13,189 This is going to be equal to-- we have the same base, x. 225 00:12:13,190 --> 00:12:19,760 We can add the exponents, x to the 1 plus 4 plus 2 power, and 226 00:12:19,759 --> 00:12:21,250 I'll add it in the next step. 227 00:12:21,250 --> 00:12:25,509 And then on the y's, this is times y to the 2 228 00:12:25,509 --> 00:12:28,100 plus 2 plus 2 power. 229 00:12:28,100 --> 00:12:29,120 And what does that give us? 230 00:12:29,120 --> 00:12:36,840 That gives us 6 x to the seventh power, y 231 00:12:36,840 --> 00:12:39,250 to the sixth power. 232 00:12:39,250 --> 00:12:41,309 And I'll just leave you with some thing that you might 233 00:12:41,309 --> 00:12:43,289 already know, but it's pretty interesting. 234 00:12:43,289 --> 00:12:44,899 And that's the question of what happens when you take 235 00:12:44,899 --> 00:12:46,709 something to the zeroth power? 236 00:12:46,710 --> 00:12:50,360 So if I say 7 to the zeroth power, What does that equal? 237 00:12:50,360 --> 00:12:52,350 And I'll tell you right now-- and this might seem very 238 00:12:52,350 --> 00:12:56,820 counterintuitive-- this is equal to 1, or 1 to the zeroth 239 00:12:56,820 --> 00:12:58,740 power is also equal to 1. 240 00:12:58,740 --> 00:13:01,600 Anything that the zeroth power, any non-zero number to 241 00:13:01,600 --> 00:13:06,060 the zero power is going to be equal to 1. 242 00:13:06,059 --> 00:13:07,229 And just to give you a little bit of 243 00:13:07,230 --> 00:13:09,320 intuition on why that is. 244 00:13:09,320 --> 00:13:12,460 Think about it this way. 245 00:13:12,460 --> 00:13:17,100 3 to the first power-- let me write the powers-- 3 to the 246 00:13:17,100 --> 00:13:19,259 first, second, third. 247 00:13:19,259 --> 00:13:23,799 We'll just do it the with the number 3. 248 00:13:23,799 --> 00:13:25,419 So 3 to the first power is 3. 249 00:13:25,419 --> 00:13:26,339 I think that makes sense. 250 00:13:26,340 --> 00:13:28,759 3 to the second power is 9. 251 00:13:28,759 --> 00:13:31,610 3 to the third power is 27. 252 00:13:31,610 --> 00:13:33,590 And of course, we're trying to figure out what should 3 to 253 00:13:33,590 --> 00:13:35,700 the zeroth power be? 254 00:13:35,700 --> 00:13:36,410 Well, think about it. 255 00:13:36,409 --> 00:13:39,039 Every time you decrement the exponent. 256 00:13:39,039 --> 00:13:41,679 Every time you take the exponent down by 1, you are 257 00:13:41,679 --> 00:13:43,159 dividing by 3. 258 00:13:43,159 --> 00:13:45,639 To go from 27 to 9, you divide by 3. 259 00:13:45,639 --> 00:13:48,000 To go from 9 to 3, you divide by 3. 260 00:13:48,000 --> 00:13:50,399 So to go from this exponent to that exponent, maybe we should 261 00:13:50,399 --> 00:13:51,629 divide by 3 again. 262 00:13:51,629 --> 00:13:54,950 And that's why, anything to the zeroth power, in this 263 00:13:54,950 --> 00:13:58,050 case, 3 to the zeroth power is 1. 264 00:13:58,049 --> 00:13:59,939 See you in the next video.