Question

Describe the error made in subtracting the two rational expressions shown:

Answer 1

You must subtract all terms of the numerator being subtracted out, not just the first term.

The negative 2 should have been subtracted out to get a numerator of x+1-x+2.

The simplified numerator of the difference should be 3, not –1.

Answer 2

The negative sign was not distributed to the 2. If it was then it would have a 3 in the numerator