divide -50-100x by 2-2x
[-50 - 100x ] / [ 2 - 2x ] =
[-50 [ 1 + 2x] ] / [2 [1 -x]] =
[-50/2] [1 + 2x] / [1 -x] =
-25[1 + 2x ] / [ 1 - x ] =
[-25 - 50x] / [1 - x]
