How Do You Multiply Fractions With Different Denominators?
To multiply fractions, multiply the first numerator by the second numerator and the first denominator by the second denominator. The product of the two numerators becomes the numerator in your answer, and the product of the two denominators becomes the denominator in your answer. When finished, always be sure to simplify your answer to its lowest term.

Write out your equation
Start by writing out your equation. For example: 1/4 x 4/5 = X.

Multiply the numerators
Multiply the first numerator by the second numerator. The product of the two numerators becomes the numerator in the answer. For example, in the equation 1/4 x 4/5 = x, multiply 1 x 4 to get 4 as the numerator.

Multiply the denominators
Multiply the first denominator by the second denominator. The product of the two denominators becomes the denominator in the answer. For example, in the equation 1/4 x 4/5 = x, multiply 4 x 5 to get 20 as the denominator. Written together, the multiplied fraction is 4/20.

Simplify your answer to its lowest term
In working with fractions, you always want to simplify your answer to its lowest term by dividing both the numerator and denominator by the greatest common factor they share. In the example 4/20, 4 and 20 both share the common factor of 4. Divide both the numerator and the denominator by the greatest common factor to find the simplest form of the fraction. Therefore, 4/20 can be simplified to 1/5.