What is the common denominator of 1/a + 1/b in the complex fraction 1/a-1/b divided by 1/a + 1/b?

something

common denominator of 1/a + 1/b is ab

however simplifying the complex fraction gives: (b-a) / (b + a)

Step-by-step explanation:

common denominator of 1/a + 1/b

should be the product of the denominators

a*b

so 1/a + 1/b = (b + a) / ab

ao

(1/a - 1/b) divided by (1/a + 1/b) = (b - a) / (ab) divided by (b+a) / ab