Question

What is the value of y?

Answer 1

y = 4

Explanation:

1. Set both equations equal to x

y=2x

x=1/2y

The other is already equal to x: x=-y+6

2. Set what is equal to x equal to each other

1/2y = -y + 6

3. Solve for y

3/2y = 6

y=4

Answer 2

y=4

Explanation:

x = -y +6

Substitute this into

y =2x

y =2 (-y+6)

Distribute

y = -2y +12

Add 2y to each side

y+2y = -2y +2y +12

3y =12

Divide each side by 3

3y/3 =12/3

y =4