9. The regular price of an item at a store is p dollars. The item is on sale for 20% off the regular
price. Some of the expressions shown below
represent the sale price, in dollars, of the item.
Expression A: 0.2p
Expression B: 0.8p
Expression C: 1 -0.2p
Expression D:p -0.2p
Which two expressions each represent the sal
price of the item?
A Expression A and Expression E
B Expression B and Expression C
C Expression B and Expression D
D Expression C and Expression D

C: Expression B and D

Step-by-step explanation:

Say the item is $100. 20% of 100 is equal to 100 (20/100)

When you simplify, it equals 20. So 20% of 100 is 20. This $20 is the amount of discount you receive.

So you have to subtract $20 from the $100 to find the sale price. The sale price is $80.

Now plug in 100 for p in each equation. The equation that equals 80 is the answer.

Only equation B and D equals 80 when 100 is plugged in.

use the power rule  

( a b ) n = a n b n

to distribute the exponent.

apply the product rule to  

3 x 2 y 3 . ( 3 x 2 ) 2 ( y 3 ) 2

apply the product rule to  

3 x 2 . 3 2 ( x 2 ) 2 ( y 3 ) 2

raise  

3

to the power of  

2 . 9 ( x 2 ) 2 ( y 3 ) 2 multiply the exponents in   ( x 2 ) 2

.

apply the power rule and multiply exponents,  

( a m ) n = a m n . 9 x 2 ⋅ 2 ( y 3 ) 2

multiply  

2   by   2 . 9 x 4 ( y 3 ) 2

multiply the exponents in  

( y 3 ) 2 .

apply the power rule and multiply exponents,  

( a m ) n = a m n . 9 x 4 y 3

⋅

2

multiply  

3   by   2 . 9 x 4 y 6

step-by-step explanation: