help please you gotta plug in 5 feet into the equation then the same for 12

Question

The function V(x)=x^3-6x^2-8x+12 finds the volume of an object with a height of x feet. What is the volume of an object with a height of 5 feet? What is the volume of an object with a height of 12 feet?

Answer 1

Just do what it says, Tyvonne. Replace the x with 5 then use a calculator to help you compute the answer:

V(x) = x³ - 6x² - 8x + 12

V(5) = 5³ - 6·5² - 8·5 + 12

V(5) = 125 -150 - 40 + 12 = -53 cubic feet

You can't have a negative volume, so the formula is incorrect for x = 5. Now you try it x = 12. Do you get a positive answer?

Answer 2

(5)^3-6(5)^2-8(5)+12 = -55

(12)^3-6(12)^2-8(12)+12 = 780

Substitute your given height for your variable, then simplify. Remember your Order of Operations (Parentheses, Exponents, Multiplication, Division, Addition, Subtraction).