This is a distributive minus sign problem and the Regents has anticipated negative sign mistakes so be careful!!

R(x) = -0.5x^2 + 800x – 100

C(x) = 300x + 250

so R(x) – C(x) is

-0.5x^2 + 800x – 100 – (300x + 250)

-0.5x^2 + 800x – 100 – 300x – 250

combine like terms and watch your signs

2 more points!!!!!