How do I solve x+2y=3 & x-y=6 using elimination?

Question

anonymous · Answer

{ x + 2y = 3
{ x - y = 6

Well since y could already be in subtraction/addition form I would multiply the second equation by a negative to. Remember, when using elimination, you're trying to use one variable. SO now, try it this way?

2 {x - y = 6}

AFTER, your systems should look like
{ x + 2y = 3
{ 2x - 2y = 12

Can you do it from there?

anonymous · Answer

So, I should try to solve one of the equations & then substitute that number into both equations?

anonymous · Answer

I think I see...you make the equations so that either x or y will cancel out when  you subtract?

anonymous · Answer

Noo, when you're using elimination you don't substitute in anything.
You see how on top of eachother there's a positive 2y and a negative 2y? What do they do? Cancel eachother out, right? In elimination you have to either subtract or add the top/bottom. Like this.

anonymous · Answer

Ok.  I understand now.  Thank you!