Question

Which of the following is a solution to the system of linear equations below 3x+y=15 and 2x+2y=6

A) (-3,6)
B) (6,-3)
C) (-6,33)
D) (6,33)

Answer 1

To find the solution to a set of linear equations, set them both to y=kx form

In this case,

1) 3x+y=15 would be y= -3x+15

2) 2x+2y=6 would be y= -x+3

3) Set them equal to each other

4) -3x+15= -x+3

5) x=6

So now we know the x coordinate as 6

Plug in this x value in one of the y= equations

6) (-3×6)+y=15

(solve for y)

y= 33

Therefore, the solution is (6,33)