Aparking garage charges $5.50 to park for 4 hours and $7.75 to park for 7 hours. if the cost is a linear function of the number of hours parked, what is the cost to park for 3 hours?

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.

-2

7 - 9 = -2

reversed:

-2 + 9 = 7