Please help me on this

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)

The scatter plot shows the number of animal cells clara examined in a laboratory in different months: plot ordered pairs 1, 20 and 2, 60 and 3,100 and 4, 140 and 5, 180 what is the approximate predicted number of animal cells clara examined in the 9th month?

Which graph correctly represents the equation  y=−4x−3? guys me iam not trying to fail summer school and will offer 40 points for who ever me with the next 3 problems and will give brainlest