23/4 + 12 6/8 = how do i figure this

The answer would be 15 1/2 and in decimal form it would be 15.5.

2 3/4 + 12 3/4 (simplify 6/8 to 3/4)

14 + 3/4 + 3/4 (add the whole numbers first)

14 + 3 + 3 over 4 (join the denominators)

14 + 6/4 (simplify)

14 + 1 2/4 (convert 6/4 to mixed fraction)

15 2/4 (simplify)

15 1/2 (simplify 2/4 to 1/2).

Turn them into improper fractions because it will make it easier. 
2 3/4 = 11/4 
12 6/8 = 102/8 
then get the same denominator
in this case you will multiply 11/4 by 2 (= 22/8)
22/8 + 102/8 = 124/8 
which can then be simplified to 15 1/2 

o you can reduce 12 6/8 to 12 3/4 
2 3/4 + 12 3/4 = (2 + 12) + (3/4 + 3/4)
= 14 + 1 1/2
= 15 1/2