How do you find a common denominator in fractions?

Ex 3/4 minus 5/8 you can multiply 3/4 to 6/8 as then subtract. You have to figure out how to make the denominators the same number and make sure to multiply top and bottom by the same number as well.

Step-by-step explanation:

The common denominator is the least common multiple (LCM) of the denominators. To find it, write the prime factorization of each denominator, then multiply the factors with the highest exponents.

For example, if the denominators are 4 and 6:

4 = 2²

6 = 2 * 3

The factors are 2 and 3. The highest exponent of the 2's is 2, and the highest exponent of the 3's is 1. So the LCM is 2² * 3 = 12.