If the equation is 3/10 x 5/8 then the answer would be 7 1/2.
Don't mind this underneath:
12/40 x 25/40
12 x 25=300
300/40=
No ------------------------------------------------ 4/5 = (4×2)/(5×2) = 8/10 8 ≠ 3 → 8/10 ≠ 3/10 → 4/5 ≠ 3/10
3/10+5/8 = 37/40
3/10 - 4/5 = 3/10 - 8/10 = -5/10 = -1/2
4/5 - 3/10 = 8/10 - 3/10 = 5/10 = 1/2
5/8 ÷ 3/16 = 10/3 or 31/3
4/5 ÷ 3/10 = 8/3 or 22/3
(5/12) / (3/8) = (5/12) * (8/3) = (5*8)/(12*3) = 40/36 = 10/9
5/8-3/10 = 25/40 - 12/40 = 13/40
(4/5)*(-3/8) = [4*(-3)]/(5*8) = -12/40 = -3/10
3/5 + 2/10 = 6/10 + 2/10 = 8/10 = 4/5.
-3/2 + 8/5 = 1/10
3/5