Answer:
-1/2y + 3
Step-by-step explanation:
2/5y - 4 + 7 - 9/10y
= (2/5y - 9/10y) + (-4 + 7)
= (2/5 - 9/10) y + 3
= (4/10 - 9/10) y + 3
= -5/10y + 3
= -1/2y + 3
