Question

3. Define a variable, write an equation, and solve the problem. Carla began a

running program to prepare for track team try-outs. On her first day she ran
3 miles, and on her second day she ran 5 miles. Since then, Carla has run 7 miles
each day. If her log book shows that Carla has run a total of 99 miles, for how
many days has Carla been running 7 miles?

Answer 1

Carla has been running 7 miles each day for 13 days.

Explanation:

Carla ran 3 miles on her first day, 5 miles on her second day and then 7 miles each day onward.

Let the number of days she ran 7 miles each day = x

Total distance run by Carla = 3 + 5 + 7(x)

= 8 + 7x

If her log book shows that she has run total distance = 99 miles

Equation representing her total run will be,

8 + 7x = 99

7x = 99 - 8

7x = 91

x =
`(91)/(7)`

x = 13 days

Therefore, Carla has been running 7 miles each day for 13 days.