Question

Amina sees a discount of 5% on a laptop. She can calculate the amount she has to pay for the laptop using the expression where b is the price of the laptop before the discount. If the price after discount is $494, which number from the set {500, 505, 510, 520, 525} is the value of b?

Answer 1

$520

Explanation:

Since this is a 5% discount, you must subtract 5 from 100% which is 95%.

This will be written as 0.95.

Expression:
`x*0.95=494\\\\0.95x=494\\\\(0.95x)/(0.95) =(494)/(0.95)`

The answer will be $520.

Answer 2

`\boxed{520}`

Explanation:

`\begin{array}{rcl}\text{ Price before discount - discount} & = & \text{sale price}\\b-0.05b & = & 494\\0.95b & = & 494\\\\b & = & (494 )/(0.95)\\\\& = & \mathbf{520}\\\end{array}\\\text{The number from the set that matches } b \text{ is }\boxed{\mathbf{520}}`