Question

the function y=5.45 + 1.05(x+7) can be used to determine the cost of in dollars for a prepaid cell phone plan of x minutes. What is the rate if change of the cost, in dollars, with respect to the number of minutes purchased?​

Answer 1

Answer:

The rate is 1.05

Explanation:

Given

$y=5.45 + 1.05(x+7)$

Required

Determine the rate

$y=5.45 + 1.05(x+7)$

Open brackets

$y = 5.45 + 1.05 * x + 1.05 * 7$

$y = 5.45 + 1.05x + 7.35$

Collect like terms

$y = 1.05x + 7.35 + 5.45$

Simplify like terms

$y = 1.05x + 12.80$

The general equation is represented as:

$y = mx + b$

Where

$m = rate$

By comparing $y = mx + b$ to $y = 1.05x + 12.80$

$m = 1.05$

Hence, the rate is 1.05