Hello! Can you please help me solve for y and not x

Question

Solve for why

 

1) 3x+9y= -7

 

2) 1/2x-3/4y=-2

Answer 1

3x + 9y = -7

Subtract 3x from both sides:

3x + 9y - 3x = -7 - 3x

9y = -7 - 3x

Divide both sides by 9:

9y/9 = (-7 - 3x)/9

y = (-7 - 3x)/9

We can factor that 1/9 into the parentheses (Though may not be necessary:

y = -7/9 - 3x/9

y = -7/9 - x/3

So you have two options for a final answer, depending on what your teacher is looking for.

 

1/2 x - 3/4 y = -2

Same process as before, we start by subtracting 1/2 x from both sides:

-3/4 y = -2 - 1/2 x

Now we multiply both sides by -4/3:

y = (-2 - 1/2 x)-4/3

Distribute:

y = ^-2*4/_-3 - ^1*-4/_2*3 x

y = 8/3 + ^2*2/_2*3 x

y = 8/3 + 2/3 x

Answer 2

3x + 9y = -7

 

9y = -3x - 7

 

y = (-1/3)x - 7/3

 

 

(1/2)x - (3/4)y = -2

 

(-3/4)y = (-1/2)x - 2

 

y = (2/3)x + 8/3