Question

The cost of apps varies directly with the number of apps purchased. Aditi bought four apps for a total of $5.16. She found the direct variation equation below for this relationship. Find her mistake and correct it. y=5.16x Choose the correct answer and justification.

Answer 1

Explanation:

The direct variation equation provided by Aditi is incorrect. The correct direct variation equation should have the form:

y = kx

where:

y represents the cost of the apps.

x represents the number of apps purchased.

k is the constant of variation, which represents the cost per app.

In Aditi's case, she bought four apps for a total of $5.16, so the correct equation would be:

5.16 = k * 4

To find the correct value of k (the cost per app), we can solve for k:

k = 5.16 / 4

k = 1.29

So, the correct direct variation equation for this relationship is:

y = 1.29x

Aditi's mistake was in providing the equation y = 5.16x, as it did not correctly represent the relationship between the cost and the number of apps purchased. The correct equation should be y = 1.29x.