Mathematics

How to add and subtract fractions


Answers

Muddymoy

4 years ago Comment

You need to find the common denominator of all of the fraction and you also have to do whatever you did to the bottom to the top. So if you times the bottom by 2 you need to times the top by two. Then once you have that you can add and subtract! 

Banaszek168

4 years ago Comment

Best answer

You need to find the common denominator.

In your question : 

4 2/7 -  2 1/5
= 4/1 * 2/7 - 2/1 * 1/5
= 8/7 - 2/5 ⇒ There, the common denominator is 7 * 5 = 35
= (8*5)/(7*5) - (2*7)/(5*7)
= 40/35 - 14/35
= (40-14)/35
= 26/35