Question

If 2x + y = -8 and -4x + 2y = -16, what is the value of y?

Answer 1

Answer:

y = -8

Step-by-step explanation:

Solve as a system of equations

   2x + y = -8       multiply this equation by 2

  -4x + 2y = -16      Do not change

Solving:   4x + 2y = -16

              -4x +2y   = -16  

                       4y = -32

                         y = -8

2x + y = -8  Solve for x

2x = -y - 8      

x = -y/2 - 8/2

x = -1/2y - 4     Substitute this into your second equation

-4x + 2y = -16

-4(-1/2y - 4) + 2y = -16

2y -16 +2y = -16

4y - 16 = -16

4y = -32

y = -8      x = -1/2(-8) -4 = 4 - 4 = 0

 Checking the answer

    2(0) + -8 = -8

     -4(0) +2(-8) = -1 6 = 0 -16 = -16