Find common factors and simplify.

a) [[$ \displaystyle\frac {3x + 9} {4x + 12} = $]]

b) [[$ \displaystyle\frac {6x - 4} {2x} = $]]

c) [[$ \displaystyle\frac {3x - 9} {x - 3} = $]]

d) [[$ \displaystyle\frac {ay - by} {y} = $]]

Take a picture of your solution and return it to the submission folder.