Question

An app developer projects that he will earn $22.00 for every 8 apps downloaded. Write an equation to represent the proportional relationship between the number of apps and the total earnings.

Answer 1

$the answer is 22/8 = x/1

Answer 2

y = ($2.750 / app) . x

Explanation:

Let's call

• x = number of apps

• y = earned money

There is a linear relation between x and y, that follows the general form:

y = a . x + b

where

a is the slope

b is the y-intercept

The slope is:

Δy / Δx = $22.00 / 8 app = $2.750 / app

The, we have

y = ($2.750 / app) . x + b

When x = 0 (no app has been sold), y = 0 (no money has been earned).

0 = ($2.750 / app) . 0 + b

b = 0

The equation representing the proportionality between x and y is:

y = ($2.750 / app) . x