00:01
For number 26, i'm going to solve this system by using elimination.
00:05
So they're already in standard form.
00:06
They're already lined up, so i'm just looking to see what i could easily eliminate here.
00:11
Well, i'm going to have to multiply both equations by something.
00:14
I guess i could get my xs to both be 60, that's probably my least common multiple.
00:19
Or i could get my ys to be 12.
00:21
I think i'll do the ys.
00:23
So if i multiply this equation by 3, because then i'll have negative 12 y.
00:34
And if i multiply this equation by 4, that would also be negative.
00:40
So i will have to make that negative 4.
00:44
So i'm just going to write these over here.
00:49
So 3 times 10x will be 30x.
00:54
3 times negative 4 .y will be negative 12y.
01:02
And 3 times 7 is 21 down here.
01:07
Negative 4 times 12 would be negative 48x.
01:16
Negative 4 times negative 3y will be positive 12y, and negative 4 times negative 15 will be positive 60.
01:32
Okay.
01:33
So now i'm just going to add these two equations.
01:37
My y's got eliminated...