find the cost of the dress

Question

a dress costs $15 more than a pair of shoes. 4 dresses cost the same as 9 pairs of shoes.

Answer 1

Assume a dress costs x dollar, a pair of shoes costs (x-15) dollar then. Now you can equate 4 dresses (4x) with 9 pairs of shoes 9*(x-15).

 

4x = 9(x-15)

 

-> 5x = 135

 

which gives you x = 27