Answer: 3/4 + 7/12 - (-4) = 3/4 + 7/12 + 4 (two minuses make a plus)
3/4 + 7/12 + 4/1 = 9/12 + 7/12 + 48/12 (4 = 4/1 or 4 divided by 1)
(to add the fractions the denominators need to be the same. Multiply both the denominator and numerator by the same number)
(9+7+48)/12 = 64/12 = 5 and 1/3 or 16/3
We can also get this answer by leaving the 4 as a whole number:
9/12 + 7/12 +4 = 16/12 + 4 = 1 and 1/3 + 4 = 5 and 1/3
If you put the sum in a calclator you also get 5 and 1/3.
Hope this helps :)
