Question:
Diane knows a phone call to a friend costs .25 for the first three minutes and .10 for each additional minute. Let y be the cost of a call that lasts x minutes. Write the slope and an equation relating x and y.
Answer:
Slope = 0.10 or
Equation relating x and y is y = 0.10x- 0.05
Step-by-step explanation:
Given:
Cost for first three minutes = 0.25 cents
Cost for each additional minute = 0.10 cents
To Find:
The slope and an equation relating x and y = ?
Solution:
Let y be the cost of a call that lasts x minutes
Then,
y = 0.25 + 0.10(x-3)
y = 0.25 + 0.10x- 0.30
y = 0.10x- 0.05-------------------(1)
In the equation
y = mx +b------------------------------(2)
m is the slope
Comparing eq(1) and(2)]
m =0.10 or