00:01
So here were given a system of two equations and were asked to use the method of substitution to solve this system.
00:09
So substitution means we saw for one variable in one equation and substituted in for the same variable in the other equation.
00:17
So now this is actually really convenient because these are both solved for why, so we could go either way.
00:23
Let's just pick away we have.
00:24
Why equals x squared? so we'll substitute in x squared for why over here.
00:32
So when we do that, we got x squared equals x plus 12.
00:38
Now, since this is a quadratic expression, it's really helpful.
00:43
Teoh rearrange the equation so that it is set equal to zero so that we can factor or use a guard attic formula, whatever we need to do to solve.
00:51
So to make that happen, we'll subtract over the x and the 12.
00:56
So we get x squared minus x minus 12 equals zero...