Let miles be the distance that Aaron could jog. Since he returned home the same way,
miles is the distance that Aaron could walk too. Then
is the number of hours Aaron spends
jogging;
is the number of hours Aaron spends
walking;
and because he spends a total of hours
jogging and walking, we can write the equality
It is a linear equation with one unknown . To solve this equation we transform it step by step:
The right answer is a formula for determining the distance. Because speed is measured in miles per hour, and time is measured in hours, a measurement unit of the distance is a mile. Let's analyze the proposed answers in terms of units. Let
and
A)
B,D,E) We can't add speed to time, so all three answers are wrong too.
C)
- mile is a right unit of distance.
If x=y, the answer should be . Only C gives this formula where x=y.
Let be distance
traveled at
miles per hour
over
hours. Then
,
,