How do you add or subtract dissimilar fractions?

Sagot :

Method 1: Trough LCD

1. Find the LCD. Multiply the denominators together. It will be your answers denominator.
2. Divide the LCD by the first fraction's denominator, then multiply by the first fraction's numerator, and then put the product above the LCD or the answer's denominator. 
3. Divide the LCD by the second fraction's denominator, then multiply by the second fraction's numerator, and then put the product above the LCD next to the first numerator.
4. Add or subtract the first numerator and the second numerator, it will be your numerator.
5. Simplify your answer.

Method 2: Cross Multiplying
1. Multiply the denominators together. It will be your answer's denominator.
2. Cross multiply.
3. Add/subtract the products you gained trough cross multiplying.
4. Simplify.


First, LCD

Second, divide the LCD to the denominator, then multiply the numerator