Lesson 12

A backpack normally costs \$25 but it is on sale for \$21. What percentage is the discount?

Find each product.

1. \(\frac25 \boldcdot (\text-10)\)
2. \(\text-8 \boldcdot \left(\frac {\text{-}3}{2}\right)\)
3. \(\frac{10}{6} \boldcdot 0.6\)
4. \(\left(\frac {\text{-}100}{37}\right) \boldcdot (\text-0.37)\)

Select all expressions that show \(x\) increased by 35%.

A:

$1.35x$

B:

$\frac{35}{100}x$

C:

$x + \frac{35}{100}x$

D:

$( 1+0.35)x$

E:

$\frac{100+35}{100}x$

F:

$(100 + 35)x$

Complete each sentence with the word discount, deposit, or withdrawal.

1. Clare took \$20 out of her bank account. She made a _____.
2. Kiran used a coupon when he bought a pair of shoes. He got a _____.
3. Priya put \$20 into her bank account. She made a _____.
4. Lin paid less than usual for a pack of gum because it was on sale. She got a _____.

Here are two stories:

• The initial freshman class at a college is 10% smaller than last year’s class. But then during the first week of classes, 20 more students enroll. There are then 830 students in the freshman class.
• A store reduces the price of a computer by \$20. Then during a 10% off sale, a customer pays \$830.

Here are two equations:

• \(0.9x+20=830\)
• \(0.9(x-20)=830\)

1. Decide which equation represents each story.
2. Explain why one equation has parentheses and the other doesn’t.
3. Solve each equation, and explain what the solution means in the situation.