C would be the answer because to find the area of a circle A=pi times radius squared and you put that in a calculator and get 50.24
I am assuming the -3 is an exponent.
y⁻³ and 5⁻³
If the exponent is a negative number, it simply means that the number is a denominator with 1 as the numerator.
y⁻³ is 1/y³
5⁻³ is 1/5³ = 1/125
The number is still raised to its exponential power but its placement is different.
5³ would be 125 or 125/1. It would be the numerator with 1 as the denominator.
total = 19.99 + 0.10(x-300) + 0.25y
x = 375
y=54
total = 19.99 +0.10(375-300) +0.25(54)
total = 19.99 + 0.10(75) + 0.25(54)
total = 19.99 + 7.50 + 13.50
total = $40.99