PM

2ax-4bx-ay-2by = (2ax-4bx) + (-ay-2by) = (2*a*x-2*2*b*x) + (-1*a*y-1*2*b*y) = 2x(a-2b) - y(a+2b) =2x(a-2b) +y (a-2b) = (a-2b) (2x+y)

1. Eliminate from the right side of the equation the term that doesn't have a in it. 2. Now a is being multiplied by 2 values. To eliminate them, do the opposite operation: divide by those 2 values. Make sure to do the same to the other side too.