1/5-2/7+3/5
https://quickmath.com/#c=simplify_algstepssimplify&v217=%25201%2F5-2%2F7%2B3%2F5
Find common denominator
5 * 7 = 35
1/5 = 7/35
- 2/7 = -10/35
3/5 = 21/35
(7-10+21)/35 = 18/35
