Question

solve by substitution method 4x+2y=-20, x=25-8y

Answer 1

4x+2y=-20
Plug in 25-8y for x in the original equation
4(25-8y)+2y=-20
get rid of the parenthesis
100-32y+2y=-20
combine like terms
100-30y=-20
subtract 100 from both sides
-30y=-120
divide each side by -30 to get y alone
y=4

Answer 2

Now that you know what y is go ahead and go back to the original problem and plug in 4 for y to find what x is.

Answer 3

4x+2y=-20
4x+2(4)=-20
4x+8=-20
4x=-28
x=-7

x=-7 and y=4

Answer 4

does that make sense?

Answer 5

yes thank you, i didnt know what do to after the -30 thank you

Answer 6

No problem just wanted to make sure you understood it:) Let me know if you need anymore help! :)