Question

3/7-4/5=

Answer 1

You need to find a common denominator. what is something both 5 and 7 go into?

Answer 2

they both go into 35.... Now lets start with 3/7
7(5)=35 and whatever you multiply by on the bottom you have to do to the top so 3(5) is 15
3/7 =15/35
do the same thing to 4/5

Answer 3

5(7)=35
4(7)=28
4/5=28/35

Answer 4

your equation should now look like this: 15/35-28/35

Answer 5

now you just have to do simple math and subtract the top
your answer should be -13/35

Answer 6

Does that make sense?