The constant value of the ratio of two proportional quantities x and y; usually written y = kx, where k is the factor of proportionality. <---definition
F(x) = x^2 - 3x
f(-8) = (-8)^2 - 3(-8)
f(-8) = 16 - (-24)
f(-8) = 16 + 24
f(-8) = 40 (Answer)
Hope this helps
For graphing, the desmos graphing calculator is a big help :))
Part A:
Expression

The constants are 15 and 100
The variables are

and

Part B:
Expression

has two terms;

and

. We know this because both have different variables attached to them
Part C:
The term

is the expression for the total earned from her allowance