This week we studied adding and subtracting rational expressions with monomial denominators, binomial and trinomial denominators. First,we have to determine the common denominator,determine the least common multiple of the denominators.

For example, + has the common denominator is 6a.

When we are adding and subtracting rational expressions with binomial and trinomial denominators,it has the same strategy as the monomial denominators. But we need to find the denominator that can factor all the denominators.