Question

1. Put 9y=-3x-39 into standard form

Answer 1

1. 9y = -3x - 39....add 3x to both sides
    3x + 9y = -39 <== standard form

2. -2x + 2y = -2. ..multiply by -1
     2x - 2y = 2 <== standard form

3. -2x = 20
     x = -20/2
     x = -10....now sub this back into the second equation

     3x - 4y = -2
    3(-10) - 4y = -2
    -30 - 4y = -2
     -4y = -2 + 30
     -4y = 28
      y = -28/4
      y = -7

solution is (-10,-7) <== solution

Answer 2

1. Put 9y=-3x-39 into standard form 
           3x + 9y = -39 ...this is standard form

2. Put -2x+2y=-2 into standard form
           2x - 2y = 2  ...this is standard form

3. Solve the system by either using substitution or elimination
{-2x=20, 3x-4y=-2}

-2x = 20
   x = -10

substitute x = -10 into  3x-4y=-2

3x-4y=-2
3(-10)-4y=-2
-30 - 4y = -2
4y = -28
  y = -7

answer
x = -10 and y = -7