The error is in the last step. In Step D, we see that we're supposed to subtract the second part from the first part. We also see we have the terms 2x-8 in the numerator on the right. Since we're subtracting, the expression should actually be -2x +8. 3 -2x +8 should be -2x +11 which is not the numerator in Step E so the last step is wrong.
