In order to explain how to do direct variations proportions, let's use the following example:
"Two apples have a cost of $3. So what is the cost of six apples?"
In this problem, if the number of apples increase, the cost also increases (in the same proportion), so we have a direct variation proportion.
The proportion of the cost and the number of apples is always the same, so we can write:
Where x represents the cost we want to find. So after writing this equation with fractions, we can solve for x:
So the final cost for six apples is $9.