Question

Lydia bought a shirt at 20% off its retail price of $40. She paid 5% tax on the price after the discount. How much did Lydia pay for the shirt?

Answer 1

we can represent "20% off" as 100% - 20%, or 1 - 0.20 as a decimal

after the discount that gives us

discounted price = (1-0.20)*(original price of shirt)

5% tax after the discount can be represented as 100% + 5%, or 1 + 0.05

applying this to the discounted price gives us

[(1-0.20)*(original price of shirt)]*(1 + 0.05)

plug in the original price of the shirt and solve

be careful with parentheses

lmk if you're having trouble