Question

Sales tax on an item is directly proportional to the cost of the item purchased. If the tax on a $500 item is $30, what is the sales tax on a $900 item?

Answer 1

30 / 500 = x / 900....$ 30 tax / 500 item = $ x tax on 900 item
cross multiply
(500)(x) = (900)(30)
500x = 27000
x = 27000/500
x = 54 <===

Answer 2

Answer: $54

Step-by-step explanation:

The equation to show the direct variation in two quantities x and y  is given by :-

$\dfrac{x_1}{y_1}=\dfrac{x_2}{y_2}$

The tax on a $500 item is $30.

Let 'x' be the sales tax on a $900 item.

Then , we have the following equation:-

$\dfrac{x}{900}=\dfrac{30}{500}\\\\\Rightarrow\ x=\dfrac{900\times30}{500}\\\\\Rightarrow\ x=54$

Hence, the sales tax on a $900 item = $54