1 00:00:00,906 --> 00:00:02,396 Rewrite the radical expression 2 00:00:02,396 --> 00:00:05,921 using rational exponents and simplify. 3 00:00:05,921 --> 00:00:09,915 So here we have the fourth root of 5 a to the fourth 4 00:00:09,915 --> 00:00:11,587 b to the twelfth power. 5 00:00:11,587 --> 00:00:16,091 The key thing to realize here is the fourth root of something 6 00:00:16,091 --> 00:00:19,853 is same thing as something to the one fourth power. 7 00:00:19,853 --> 00:00:23,475 Or in particular, or in general, the nth root something 8 00:00:23,475 --> 00:00:27,562 is the same thing as that something to the 1 over n power. 9 00:00:27,562 --> 00:00:29,745 So we can just apply that over here: 10 00:00:29,745 --> 00:00:30,665 the fourth root of all of this 11 00:00:30,665 --> 00:00:35,133 is equal to 5 a to the 4th, b to the 12th power, 12 00:00:35,133 --> 00:00:38,166 all of that to the one fourth power. 13 00:00:38,166 --> 00:00:41,215 And then we also know if we take the product of things, 14 00:00:41,215 --> 00:00:43,491 and then raise them to some exponent, 15 00:00:43,491 --> 00:00:46,928 that's the same thing as raising each of the terms in the product 16 00:00:46,928 --> 00:00:47,998 to the exponent first, 17 00:00:47,998 --> 00:00:50,550 or each of the things that we're taking the product of 18 00:00:50,550 --> 00:00:52,825 to that exponent, and then multiplying. 19 00:00:52,825 --> 00:00:55,057 So let's do that. 20 00:00:55,057 --> 00:00:57,302 So 5, so this is the same thing as 21 00:00:57,302 --> 00:00:59,039 5 to the 1/4 power 22 00:00:59,039 --> 00:01:02,430 times a to the fourth to the 1/4 power 23 00:01:02,430 --> 00:01:07,222 times b to the 12th to the 1/4 power. 24 00:01:07,222 --> 00:01:10,147 Now 5 to the 1/4, 25 00:01:10,147 --> 00:01:11,329 I don't know what that is, 26 00:01:11,329 --> 00:01:13,605 so I'll just keep that as the cube root, 27 00:01:13,605 --> 00:01:15,805 well, we could leave it as 5 to the 1/4, 28 00:01:15,805 --> 00:01:17,876 and that's not not simplified. 29 00:01:17,876 --> 00:01:23,027 or we can just rewrite it again as the fourth root of 5. 30 00:01:23,058 --> 00:01:25,446 a to the fourth to the 1/4 power: 31 00:01:25,446 --> 00:01:28,740 if your raise something to a power and then another power, 32 00:01:28,740 --> 00:01:30,151 and raise that to another power, 33 00:01:30,151 --> 00:01:35,267 that's equivalent of raising a to the four times 1/4 power. 34 00:01:35,267 --> 00:01:36,329 So let me just write that down. 35 00:01:36,329 --> 00:01:41,200 This is, so times a to four times 1/4 power. 36 00:01:41,200 --> 00:01:44,234 And then finally, this right over here, 37 00:01:44,234 --> 00:01:46,928 using the same exact exponent property, 38 00:01:46,928 --> 00:01:50,504 this is b to the 12th times 1/4 power. 39 00:01:50,504 --> 00:01:53,151 So all of this simplifies to, 40 00:01:53,151 --> 00:01:55,241 and I'll change the order here, 41 00:01:55,241 --> 00:01:59,112 so you have the fourth root of 5, 42 00:01:59,112 --> 00:02:02,903 and then you have a to the fourth times 1/4 power 43 00:02:02,903 --> 00:02:05,368 so that's just, this simplifies to a to the first power 44 00:02:05,368 --> 00:02:07,059 which is really just the same thing as a. 45 00:02:07,075 --> 00:02:08,902 So that's just a. 46 00:02:08,902 --> 00:02:13,882 And then we have b to the 12 times 1/4 power. 47 00:02:13,882 --> 00:02:16,454 Well, 12 times 1/4 is just three. 48 00:02:16,454 --> 00:02:19,036 So that's b to the third power. 49 00:02:19,036 --> 99:59:59,999 So it's a, b to the third power times the fourth root of 5.