Solveing using the addition method

Question

-5x-9y=19
8x-7y=-9

Answer 1

1st times 8 ----> -40x - 72y = 152
2nd times 5 ----> 40x - 35y = -45
add them
- 107y = 107
y = -1
back into 1st:
-5x + 9 = 19
-5x = 10
x = -2

Answer 2

We can solve x or y, so I'll pick y. Let's get rid of x by multiplying the top equation by 8 and the bottom equation by 5:

8(-5x - 9y = 19)
5(8x - 7y = -9)

-40x - 72y = 152
40x - 35y = -45
---------------
.... -107y = 107
.........y = -1

I'll let you take it from here to figure out the value of x. Check solutions with the original equations. It always helps to check your work!

I hope this will help get you started.