Answer:
-5 3/5
Step-by-step explanation:
John's error was in adding the whole number and fractional portions separately, the fractions must be converted to improper fractions with common denominators to be added or subtracted properly so
(-7 4/5) + (2 1/5), convert to improper fractions
-39/5 + 11/5, both fractions have common denominator so we can continue
-39 + 11 = -28, so -39/5 + 11/5 = -28/5, convert back to proper fractions
-28/5 = (-25/5) + (-3/5) = -5 3/5
