Rearrange the following to make 'W' the subject: aw + 3 = 4(bw + 5)

aw + 3 = 4(bw + 5)    Let's get rid of those brackets...
aw + 3 = 4bw + 20    Now we rearrange...
aw - 4bw = 17        Factorise...
w(a - 4b) = 17        Final rearrange...
w = 17 / (a - 4b)      Done.