00:01
Hello.
00:02
This problem asks us to compare and contrast the substitution method with the elimination method for solving a system of equations.
00:10
So the first thing is, what do they have in common? so if i write two different systems, so over here i'm going to do x plus 2y equals 6 and negative x plus 2y is equal to 12, let's say.
00:28
And then over here i'm going to have a different system.
00:34
Let's say y is equal to 2x plus 2 and y is equal to 5x minus 1.
00:42
So what both methods, this is the elimination method i would use here.
00:51
And this would be a substitution problem.
00:55
Substitution problem over here.
00:57
And the reason why is this.
00:58
Over here, if you look, i have, if i add these two equations together, x minus x is zero.
01:09
And so, and then this would be 4y is equal to 18...