sums and differences of rational algebraic expression please answer the following 9ab/cd^2 - 7ab/cd^2 another 3/x-1 - 2/x-1 another is 4x/4x-y - 2x/4x-y another is 3x/2y - 3x-2y/3x+2y another is 8/3x - 3/4x + 4/12x another is x-3/3x+1 + x+5/3x+1

Answer 1

Take advantage of, or create, common denominators and add the numerators. These are the same kind of problems that Reiny has already answered for you.

Answer 2

2/24 1/4