# Dan and Kate used two different treadmills to exercise. The total distance walked between them was 3.7 miles. How do you state what quantity the variable x represents and express the second quantity in terms of x?

Mar 19, 2017

If $x$ is the distance Dan walks, then $3.7 - x$ is the distance Kate walks.

#### Explanation:

Since we are not given any reason to do otherwise, we can define $x$ as the distance one of them (either one, it doesn't matter) walked. Let's use Dan's mileage for this:

$x$ = distance walked by Dan. This is the first expression needed.

Now, to find an expression for Kate's walk. You can do it this way:

Now let $y$ represent the distance Kate walks.

Since the total distance is 3.7 miles, it must be that

$x + y = 3.7$

So, $y = 3.7 - x$

There is your second expression. The distance Kate walks is $3.7 - x$