Answer:
18.2 = 4mm + 5
Explanation:
Since we are looking for a total amount of miles based on a given number of days and variable, we need to set up an equation.
We're already given an amount she has ridden, so we need to make sure that the average number we are given for the remaining 4 days is not influenced, thus why we add a "+5" at the end of the equation. If this makes things confusing, you could always subject 5 from 18.2 to get the equation: 13.2 = 4mm
Since we are looking for mm in this scenario, we can isolate mm by diving both sides by 4.
13.2 / 4 = 4 / 4 mm
3.3 = mm
While we are given the answer 3.3 (which is how many miles they would need to ride for the next 4 days per day), that is not what the problem is asking for. We don't want the answer, we want how to set up the equation for this to be possible, so keep that in mind for questions such as these.