What has to be added to the sum of 5/8 and 8/5 to get 3

31/40 has to be added to the sum of 5/8 and 8/5 to get 3.

Step-by-step explanation:

Solve this equation:  5/8 + 8/5 + f = 3, where f is the number that has to be added to the sum of 5/8 and 8/5.

The LCD of 5/8 and 8/5 is 40; thus, 5/8 + 8/5 = 25/40 + 64/40 = 89/40.

Then 89/40 + f = 120/40 (where 120/40 is equivalent to 3).

Subtracting 89/40 from both sides yields the desired result:

f = (120 - 89)/40 = 31/40

31/40 has to be added to the sum of 5/8 and 8/5 to get 3.

(x) - (y) = (1 + 4i)