How do you solve 9x-4y = -599x4y=59 and 4x+27 = y4x+27=y using substitution?

1 Answer
Aug 26, 2016

x=-7x=7 and y=-1y=1

Explanation:

We have the first equation as 9x-4y=-599x4y=59 and second equation 4x+27=y4x+27=y.

The second equation gives y=4x+27y=4x+27 and substituting this value of yy in first we get

9x-4(4x+27)=-599x4(4x+27)=59 or

9x-16x-108=-599x16x108=59 or

-7x=-59+108=497x=59+108=49 or

x=-7x=7 and

y=4×(-7)+27=-28+27y=4×(7)+27=28+27

or y=-1y=1