To solve this equation, first combine like terms on the left side:

29 + 959 - y + 15 = 75

Subtract 29 and 15 from both sides:

959 - y = 31

Subtract 959 from both sides:

-y = -928

Divide by -1 to solve for y:

y = 928

Therefore, the solution to the equation is y = 928.