1
00:00:00,721 --> 00:00:02,113
Solve for x and y.

2
00:00:02,113 --> 00:00:03,936
We have two equations and two unknowns

3
00:00:03,936 --> 00:00:10,602
Negative 3y plus 4x= 11 and y plus 2x = 13

4
00:00:10,602 --> 00:00:13,921
What we could do is try to solve this using- using elimination

5
00:00:13,921 --> 00:00:16,233
Maybe we could add these two equations together

6
00:00:16,233 --> 00:00:17,933
to get some variables to cancel out.

7
00:00:17,933 --> 00:00:21,200
But if we just add y and -3y, those will cancel out.

8
00:00:21,200 --> 00:00:24,133
And if we just add 2x and 4x, THOSE will cancel out

9
00:00:24,133 --> 00:00:26,600
But maybe we can SCALE one of these equations

10
00:00:26,600 --> 00:00:28,867
so that we WILL get some cancellation.

11
00:00:28,867 --> 00:00:34,400
If this y could somehow become a 3y, then 3y and -3y would cancel out.

12
00:00:34,400 --> 00:00:37,731
So the easiest way to t-turn this y into a 3y would be to just

13
00:00:37,731 --> 00:00:41,846
multiply this entire equation so we don't actually change the information in it

14
00:00:42,015 --> 00:00:45,646
To multiply this entire equation by 3.