1) Simplest common denominator: When dividing by fractions, first determine the common denominator of the denominator. Generally, the product of the highest power of all factors of each denominator is taken as the common denominator, which is called the simplest common denominator.
For example, the simplest common denominator of 2x/(x-5) and 3x/(x+5) is (x-5)(x+5).
3/2a？ B and (a-b)/ab? The simplest common denominator of c is 2a? b？ c
2) simplest fraction: The fraction with no common factor between numerator and denominator is called simplest fraction.
3) Common factor: The common factor of the numerator and denominator of a fraction is called the common factor.
For example (3x? +3xy)/6x？ In, the numerator can be changed to 3x(x+y), and the common factor of denominator of numerator is 3x.