Answer: you save $24.7 by buying the headphone at store A
Explanation:
The price of a pair of headphones
at store A is 98.80. The price of a pair of headphones at store A is 4/5 the price at store B. Let x represent the price of a pair of headphones at store B. It means that
4/5 × x = 98.80
4x/5 = 98.80
Multiplying the left hand side of the equation and the right hand side of the equation by 5, it becomes
4x = 98.80 × 5 = 494
x = 494/4 = 123.5
The amount saved by buying the headphone at store A is 123.5 - 98.80 = $24.7