Question

Find the common denominator needed to subtract the following fractions. 5/6 -2/7 =

Answer 1

Answer:

42

Step-by-step explanation:

We need to find the Least Common Multiple (that isn't 0) between 6 and 7. To do this, list each number's multiples.

Multiples of 6: 0, 6, 12, 18, 24, 30, 36, 42, 48, 54

Multiples of 7: 0, 7, 14, 21, 28, 35, 42, 49, 56, 63

Their LCM is 42. Now, we multiply the fractions so the denominators are both 42. !You have to multiply both the numerator and denominator by the same number! For 6, 6*7 is 42, so you multiply both 6 and 5 by 7. When you do this, you get 35/42. For 7, 7*6 is 42, so you have to multiply both 7 and 2 by 6. When you do this, you get 12/42. The new problem is 35/42-12/42.

Hope this helps!