to add, convert the denomenators to the same numjber by finding the least common multiple of 12 and 8
so factor
12=2 times 2 times 3
8=2 times 2 times 2
LCM=2 times 2 times 2 times 3=24
so convert so bottom number=24
5/12 times 1 or 2/2=10/24
3/8 times 3/3=9/24
so
5/12+3/8=10/24+9/24=19/24
the answer is 19/24