3x + 2y 1

-------- = ---

4x + y 3

- x = 7y/13
- x = 7y/5
- x = -7y
- x = -3y
- x = 3y/5
- x = -5y/13
- x = -y

Cross multiply:

3(3x - 2y) = 4x + y

Multiply the left side through

9x - 6y = 4x + y

Subtract 4x from each side and add 6y to each side

5x = 7y

Divide each side by 5 to isolate x, the subject of an equation is the variable to the left

**x = 7y/5**