How do you translate this:
45% of two-fifteenths of the product of (x+1) and one-twelfth y

45% of two-fifteenths is equal to 0.45 * 2/15
the product of (x+1) and one-twelfth is equal to (x+1) * 1/12 or (1/12x + 1/12)
Multiply them together to get your answer.

In word problems "of" means multiply

The answer is