3x+7y=-9. 2x+5y=-7

Question

2 separate equations. Find x and y.

Answer 1

So, we need either the x or y to be opposites so that they cancel out when we add the equations together.

 

Let's multiply the first by -2 and the 2nd by 3.

 

-6x - 14y = 18

6x + 15y = -21

 

When we add the two together, we get...

 

y = -3

 

Now substitute that back into either equation and solve for x.