Question

Garvey’s Electronics store is having a storewide sale. For a television set with a regular price of x dollars, a 15 percent discount is equal to $30. Which of the following equations could NOT be used to determine x?

0.15x = 30

0.85x = x – 30

0.15x = x – 30

x – 0.15x = x – 30

Answer 1

0.15x=x-30

Explanation:

Let

x-----> the regular price

we know that

15%=15/100=0.15

so

0.15x=30

x=30/0.15=$200

Verify each case

case a) 0.15x=30

x=30/0.15=$200

therefore

The equation could be used to determine x

case b) 0.85x=x-30

x-0.85x=30

0.15x=30

x=30/0.15=$200

therefore

The equation could be used to determine x

case c) 0.15x=x-30

x-0.15x=30

0.85x=30

x=30/0.85=$35.29

therefore

The equation could not be used to determine x

case d) x-0.15x=x-30

-0.15x=-30

0.15x=30

x=30/0.15=$200

therefore

The equation could be used to determine x