1. 3/5 + 7/10 = 6/10 + 7/10 = 13/10
2. 4/5 - 6/15 = 12/15 - 6/15 = 6/15 or 2/5
3. 6/8 x 4/5 = 24/40 or 3/5
4. 9/10 + (-4/5) = 9/10 - 4/5 = 9/10 - 8/10 = 1/10
5. 2 4/8 x 3 2/4 = 6 8/32 or 6 1/4
hope it helps;)
