To simplify the expression 3(y + 4) + (2y – 5) – 1(y – 2), we can apply the distributive property and combine like terms:

3(y + 4) + (2y – 5) – 1(y – 2)
= 3y + 12 + 2y – 5 – y + 2 (distributing the 3, 1, and -1)
= (3y + 2y – y) + (12 – 5 + 2) (combining like terms)
= 4y + 9 (simplifying further)

Therefore, the simplified expression is 4y + 9.