Question

X - Tables y - Chairs312520288321040As a direct proportion equation

Answer 1

In order for a relation to be a proportion, you will need that every quotient to be constant. In this case it is necessary that

`(12)/(3)=4,\text{ }(20)/(5)=4,\text{ etc}`

are the same. Since this is true, then it is a proportion, and the constant of proportionality is 4, that is

`y=4x\text{.}`

You can check this by subtitution, and his is the equation that gives you the proportion relation.