A cell phone company charges a $20 fee every

month and $0.01 for ten

minutes spent talking on

the phone. Write an

equation to model the cost

of a monthly cell phone bill

for the linear function.

C = 20 + 0.001x

C = $20 + $0.001x

Step-by-step explanation:

Let x represent the number of minutes spent talking on the phone.

Given;

Fixed monthly charge F = $20

Charge per 10 minutes V = $0.01

Charge per minute = V/10 = $0.01/10 = $0.001

The equation to model the cost of a monthly cell phone bill;

Total cost = fixed cost + variable cost

C = F + (V/10)x

Substituting the values;

C = 20 + 0.001x

3< x< 5

step-by-step explanation:

|x - 4| < 1

there are two solutions, one positive and one negative.   remember to flip the inequality when taking the negative solution

x-4 < 1       x-4 > -1

add 4 to each side

x-4+4 < 1+4       x-4+4 > -1+4

x< 5                 x> 3

3< x< 5