Question

The price of a brick today is 49¢. This is 3¢ less than 4 times the price 20 years ago. What was the price 20 years ago?

Answer 1

`x=13`

Explanation:

Let `y` equal the price today.
Let `x` equal the price 20 years ago.
The following equations are based upon the two statements above.
`y=49`
`4x-3=y`
Substitute `y` in the second equation.
`4x-3=49`
Solve for `x`
Add `3` to each side.
`4xcancel(-3+3)=49+3`
`4x=52`
Divide each side by `4`.
`(4x)/4=52/4`
`x=13`