Question

A pack of gum costs 50 cents. That is 4 cents less than four times what the pack cost 15 years ago. Write an equation that could be used to find the cost of the gum 15 years ago.Then solve and find the price of gum 15 years ago.
Please show all the work. thx.

Answer 1

Y = (x+4)/4 where y represents the amount fifteen years ago and x represents the current price. 

y = (50+4)/4 
y = 13.5

Answer 2

Let the price of the gum 15 years ago was = x cents

Now it is given that the current price of the gum is = 50 cents

And the question says

That is 4 cents less than four times what the pack cost 15 years ago

So the equations comes out to be ,

4x -4 = 50

Now we have to solve for x

add 4 to both sides

4x = 54

Divide both sides by 4

x=13.5

Hence 15 years ago , the cost of the gum was 13.5 cents