4x + 8y = 20

- 4x + 2y = - 30

4x + 8y = 20

- 4x + 2y = - 30

find y first

in order to find y eliminate x

add the two equations together

4x+-4x+8y+2y = 20+-30

4x-4x+8y+2y = 20-30

10y = - 10

divide both sides by 10 to get y by itself

10y/10 = - 10/10

y = - 1

find x by using the substitution method

- 4x + 2y = - 30

-4x+2 (-1) = -30

-4x-2 = - 30

move - 2 to the other side

sign changes from - 2 to + 2

-4x-2+2 = - 30+2

-4x = - 28

divide both sides by - 4

-4x/-4 = - 28/-4

x = 7

answer:

(7,-1)