A pack of gum costs 75 cents. That is 3 cents less than three times what the pack cost 20 years ago. Which equation could be used to find the cost of the gum 20 years ago?

Respuesta :

tiza
let's assume the cost 20 years ago equals x

3x - 3 = 75

or

x = 75 / 3 + 3
75=3c-3
(c stands for cost 20 years ago)