Answer:
1/4
Step-by-step explanation:
The inverse function tells you the input value that corresponds to the given output value of the function.
<h3>Application</h3>
You want f^-1(3), which is the value of x such that f(x) = 3.
f(x) = 3 = 4x +2
1 = 4x . . . . . . subtract 2
1/4 = x . . . . . divide by 4
The inverse function of 3 is 1/4:

Answer:
The costs of the plan are $0.15 per minute and a monthly fee of $39
Step-by-step explanation:
Let
x ----> the number of minutes used
y ----> is the total cost
step 1
Find the slope of the linear equation
The formula to calculate the slope between two points is equal to

we have the ordered pairs
(100,54) and (660, 138)
substitute


step 2
Find the equation of the line in point slope form

we have

substitute

step 3
Convert to slope intercept form
Isolate the variable y

therefore
The costs of the plan are $0.15 per minute and a monthly fee of $39