Question

antwan is purchasing a cell phone plan. the flat cost of the plan is $50.00 per month, and there is an additional fee of $20.00 per phone line. using a table and graph, determine how many phone lines are on the plan if antwan pays $150 per month. (1 point)

7

6

2

5

Explanation:

Step1: Define the cost function

Let \( x \) be the number of phone lines. The total cost \( C \) is the flat cost plus the cost per line: \( C = 50 + 20x \).

Step2: Substitute the total cost

We know \( C = 150 \), so substitute into the equation: \( 150 = 50 + 20x \).

Step3: Solve for \( x \)

Subtract 50 from both sides: \( 150 - 50 = 20x \) → \( 100 = 20x \). Divide both sides by 20: \( x = \frac{100}{20} = 5 \).

Answer:

5 (corresponding to the option "5")