Question

Arbara sells iced tea for $1.49 per bottle and water for $1.25 per bottle. She wrote an equation to find the number of drinks she needs to sell to earn $100. 1.25x + 1.49 = 100 What error did Barbara make in writing the equation?

Answer 1

if ice tea is lets say y (ice tea = y) and water is x (water = x) then the answer is 
1.25x + 1.49y = 100
the error is that she forgot the second variable(y).