Question

solve each system by substitution
Please show how you got it and also how you found Y... Thanks :)
x+7y=0
2x-8y=22

Answer 1

x=-7y (took the first equation and solved y for x)
2(-7y)-8y=22 (plug in the new equation for x)
-14y-8y=22 (simplify)
-22y=22 (simplify)
y=-1(divide both sides by -22)

Answer 2

x+7(-1)=0 (plug in -1 for y)
x-7=0
x=7

Answer 3

why did the 7 turn (-)

Answer 4

I plugged in the new y value, which we found out was negative one. 7*-1=-7

Answer 5

thanks

Answer 6

yup!