In the equation c=2.5r+15 with is the constant and which is the coefficient

constant = 15

coefficient = 2.5

Step-by-step explanation:

A constant does not change value no matter what, and a constant's derivative is always 0. In this equation, 15 does not change with any variable, therefore it is the constant.

A coefficient is the number that comes before a variable. In the equation, r is a variable, and the number 2.5 comes before it, making it the coefficient.

13.46

step-by-step explanation:

16.80 x .20 = 13.46

i believe it's a.

i'm not sure on this one, most likely correct.