3: Keith purchases a cell phone plan, which includes a cell phone and cell phone service. He makes a deposit of $100 for the cell phone and then pays $45 per month for the cell phone service. A. Create an equation to model the total amount of money, y, in dollars, Keith spends on the cell phone and plan after x months. B. How much money does Keith spend per year for cell phone service?

y = 100 + 45x

$640

Step-by-step explanation:

y = 100 + 45x

One year = 12 months

y = 100 + 45(12)

y = 100 + 540 = 640

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.

i think the answer is b