Question

Maria buys a dress that is 15% off. She then uses a coupon to get an additional 10% off the sale price. She pays $91.80 for the dress. What was the original price of the dress? PLZ INCLUDE STEPS SO I KNOW HOW TO DO IT!!

Answer 1

$120

Explanation:

First add the 10% back, to do so make it a decimal by moving the . over to the left twice.

Now setup the equation OP= New price/(1-discount)

91.80/(1-.10)=102

So the price before the 10% discount is $102

Now set it up again with the new numbers.

102/(1-.15)=120

So the original price before all discounts was $120

Answer 2

Steps:

*Let p = original price

So firstly, how would we get the price when it's 15% off? You would find multiply the price by 0.15 (15% in decimal form) and then subtract the product from the original price. This can be represented as
`(p-p*0.15)`

Next, we would have to use the 10% off when the dress is already 15% off. The process is similar: Multiply 0.10 (10% in decimal form) with 15% off dress, then subtract the product from the 15% off price. This can be represented as
`(p-p*0.15)-0.10(p-p*0.15)`

Now since the price is equal to $91.80, we would equal the prior expression to 91.80 as such:
`(p-p*0.15)-0.10(p-p*0.15)=91.80` From here we can solve for p.

Firstly, solve the multiplication inside of the parentheses:

`(p-0.15p)-0.10(p-0.15p)=91.80`

Next, distribute -0.10 to (p - 0.15p):

`p-0.15p-0.10p+0.015p=91.80`

Next, combine like terms:

`0.765p=91.80`

Lastly, divide both sides by 0.765:

`p=120`

Answer:

The original price of the dress was $120.