We can calculate the mmc between 8 and 12
8, 12 | 2
4 , 6 | 2
2 , 3 | 2
1 , 3 | 3
1, 1 | 1
mmc = 2 × 2× 2×3
mmc = 24
24 ÷ 8 = 3
And
24 ÷ 12 = 2
3/8 + 5/12 = ( 3× 3+ 5×2)/24
= (9 + 10)/24
= 19 / 24
Answer = 19/24
Another way of calculating would be to multiply the denominator and multiply the extremes.
3/8 + 5/12 = ( 3 × 12 + 8×5)/8×12
= ( 36 + 40)/96
= 76/96
Division by 2
= 38 / 48
Division by 2
= 19 / 24
I hope this has helped.