add and simplify

1. a^2/2 + 3a^2/8
2. 4c/15 + 8c/25

i need help can someone explain please

2 answers

4 a^2/8 + 3 a^2/8 = 7 a^2/8

15*5 = 75 and 25*3 = 75
so
5/5 * 4 c/15 + 3/3 * 8 c/25

20 c/75 + 24 c/75 = 44 c/75
Thanks!