Instead of subtracting 2x-y=-8 from 2x+6y=6, what equation can you add to get the same result? Explain.

Question

Instead of subtracting 2x-y=-8 from 2x+6y=6, what equation can you add to get the same result? Explain.

Answer 1

You can multiply the first equation by 6 and then add them together.

 

12x - 6v = -48

 2x  +6y = 6

 

14x       = -42

 

  x = -3

 

2(-3) - y = -8

 

-6 - y = -8

 

-y = -8 + 6

 

-y = -2

 

y = 2

 

(x=-3, y = 2)