Tri City sells four times as many dishwashers as Solly Company. The difference between their sales is 96 dishwashers. How many dishwashers did each sell?

First of all, we have to set variables to represent the given in the problem. We have to set variables for the sales of Tri City and the sales of Solly Company. Hence,

let T be the sales of the Tri City Company and

let S be the sales of the Solly Company

Secondly, we are going to translate into mathematical terms the relationship between the two variables. Hence,

T=4S (1)

T-S=96 (2)

We have two linear equations and two unknowns so this problem is answerable. We substitute equation (1) into equation (2) to give us

4S-S=96

3S=96

S=32

Solving for T gives us

T-32=96

T=96+32

T=128

So, Tri City sold 128 dishwashers while Solly Company sold 32.