Question

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

Answer 1

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)