Exercise 73 Page 184

This question mentions three different costs of a pair of pants. Let's introduce variables for these costs.

The question gives information about the relationship between these costs. Both the store price and the sale price is compared to the purchase price.

• The store price is 40 % more than the purchase price. This can be rephrased to saying that the store price is 140 % of the purchase price. Using the variables we introduced, this can be expressed using an algebraic equation.

  p=1.4c

  • The sale price is 30 % less than the purchase price. This can be rephrased to saying that the sale price is 70 % of the purchase price. Using the variables we introduced, this can be expressed using an algebraic equation.

  s=0.7c

  Finding the Purchase Price

  Since the store price is given as $49, we can use the first equation to find the purchase price.
  p=1.4c

  Substitute

  p= 49

  49=1.4c

  ▼

  Solve for c

  DivEqn

  .LHS /1.4.=.RHS /1.4.

  49/1.4=c

  CalcQuot

  Calculate quotient

  35=c

  RearrangeEqn

  Rearrange equation

  c=35
  It costs $35 for the store to buy the pants.

  Finding the Sale Price

  Once we know the purchase price, we can use the second equation to find the sale price.
  s=0.7c

  Substitute

  c= 35

  s=0.7( 35)

  Multiply

  Multiply

  s=24.5
  It costs $24.50 the employees to buy the pants after the sale. The correct answer is J.