Answer:

Step-by-step explanation:
First, let's change those variables to x and y, just for the sake of convenience. In order to find the inverse of a function algebraically, switch the x and y coordinates, then solve for the new y. Letting y = A(n) and x = n (we will switch them back when we're done):
y = 3x - 20. This is linear; a line with a slope of 3 and a y-intercept of -20. When we switch the x and the y, we get:
x = 3y - 20. Now we solve for the new y. Begin by adding 20 to both sides:
x + 20 = 3y. Now divide both sides by 3:
, or to write it in slope-intercept form, like the function you started with:

This is also a line, with a slope of 1/3 and a y-intercept of +20/3
Now, replacing:

That is how to write the inverse using function notation. The little -1 as an exponent tells us that this is the inverse of the function A(n).
Answer:
-4
Step-by-step explanation:
just add both of the sides then divide
Answer:

Step-by-step explanation:
Given


Required
The cost of units used
First, calculate the number of units used.



Next, multiply the units used by the cost per units,
Since the cost per unit is not given, we assume that it is x.
So, the total cost is:



Answer:
45 feet
Step-by-step explanation:
Use ratios:

x = 540 inches
divide by 12 to get 45 feet