At a sale, dresses were sold for $90 each. This price was 75% of a
dress's original price. How much did a dress originally cost?

A dress originally costs $120

Step-by-step explanation:

To find the original cost of the dress, we will follow the steps below;

let x represent the original cost of the dress

75% of x  = $90

 ×    x   = $90

 =   $90

MULTIPLY both-side of the equation by 100

× 100 =   $90×100

At the right-hand side of the equation, 100 will cancel out 100, leaving us with just 75x

75x = $9000

DIVIDE both-side of the equation by 75

75x/75 = $9000/75

At the left-hand side of the equation 75 will cancel-out 75 leaving us with just x

x=  $9000/75

x = $120

A dress originally costs $120

its 50 miles away from the starting point