Question

The formula C = 20x + 5 models the cost of New York Yankees T-shirts, where C is the cost and x is the number of shirts sold. Choose ALL TRUE statements in the context of this situation.
The total cost of T-shirts sold represents the domain
This model is a relation but not a function
The total cost of T-shirts sold represents the range
The cost of 20 T-shirts is $405.00 This model is a function

Answer 1

First 2 are false
Last 2 are true..

Answer 2

1)
False, it represent range, 
2)
False, It is a function
3)
True, c represent range
4)
x=20
C=20*20+5=405
It is a function, for amount we assigne one value.