solving for variables

Question

I am learning about solving for variables,the equation is "y= -3/7x-9" solving for X and the answer I got was "x=-7/3y-21" so my question is, how did they get to this answer?

Answer 1

Here's another option for you:

 

y = (-3/7)x - 9

 

Add 9 to both sides

y + 9 = (-3/7)x

 

Multiply both sides by (-7/3)

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

 

Simplify

x = (-7/3)y - 63/3

x = (-7/3)y - 21

 

 

Answer 2

1. Add 9 to both sides of the equation 

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

2. Multiply both sides of the equation by 7

7y + 63 = -3*x

3. Divide both sides of the equation by -3

(-7/3)y-21 = x