5. Ettienne wants to calculate the cost of his electric bill. He is on a standard use plan that has a graduated fee schedule.
Standard Use Plan
8.5 cents/kWh for the first 400 kWh
12 cents/kWh for the next 400 kWh
14.5 cents/kWh for anything over 800 kWh
How much will his bill be if he uses 1.395 kWh? Round to the nearest dollar.

the correct option is:

b. a value of the variable that makes the polynomial equal to zero.

the root or roots of a polynomial are the values of the variable that makes the polynomial equal to 0. we can find the roots of a polynomial making the expression equal to 0 and then, isolating the variable (it it has just one variable).

for example, given the following polynomial:

the root or zero of the polynomial, can be found by making the expression equal to 0, and then, isolating the variable, so, finding the root we have:

therefore, we have that the root of the polynomial is equal to 2.

we must remember that the number of roots that a polynomial can have, will depend on the degree of the polynomial, a first degree polynomial have will have one single root, a second degree polynomial (quadratic expression) may have two roots and so.

hence the correct option is:

b. a value of the variable that makes the polynomial equal to zero.

have a nice day!