Question

Find the solution of this system of equations.

Separate the x- and y-values with a comma.
x= 12 + y
18x – 12y= 18

Answer 1

x= 12 + y
18x – 12y= 18

substitute x= 12 + y into 18x – 12y= 18

18x – 12y= 18
18(12 + y) – 12y= 18
36 + 18y - 12y = 18
6y =-18
y = -3

x= 12 + y
x= 12 -3
x = 9

solution (9, -3)

Answer 2

Since we have x=12+y simply use this value of x in the other equation to eliminate the x variable...

18(12+y)-12y=18 perform indicated multiplication on left side

216+18y-12y=18 combine like terms on left side

216+6y=18 subtract 216 from both sides

6y=-198 divide both sides by 6

y=-33, which makes x=12+y become:

x=12-33

x=-21

So the solution to this system of equations is the point (-21, -33)