Question

The amount of sales tax on a purchase varies directly as the price of the item varies. If a computer costs $400 before tax and the tax is $30 tax, which of the following equations is a correct step in solving for how much tax is needed for a computer that costs $500?
A. 400 over 30 = 500 over Y
B. 400 over 30 = X over 500
C. 30 over 400 = 500 over Y
D. 30X = 200,000

Answer 1

To set up a proportion, you would need to put the same variables across from eachother so it would be:
amount before tax amount before tax
--------------- = ---------------
tax tax
In this case it would be:
400 500
--- = ---
30 y

Answer 2

Thank you

Answer 3

You're welcome:)