1. In direct variation, when a quantity varies directly as another quantity , the value of the quantity increases when increases, and decreases when decreases.
2. Based on this information, let's see the expression given in the problem:
3. As you can see, if you give values to , the value of will have a direct variation. When increases, increases, and when it decreases decreases.
From the question, we are informed that Martin would like to start training to run a marathon and that first week he runs a total of 15 miles.
We are further told that he would like to run 0.3 more miles each week than the week before. There, the number of miles that Martin will run the second week will be: