Answer:
(a) 8 1/2 ÷ 1/4
Step-by-step explanation:
Katie's total mileage is the product of the miles per day (1/4) and the number of days (n).
miles = (1/4)n
If Katie jogged 8 1/2 miles, then we have ...
8 1/2 = (1/4)n
We find the value of n (the number of days) by dividing both sides of this equation by the coefficient of n:
(8 1/2) ÷ (1/4) = n
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Additional comment
If you consider the units, you know that the only possible operation is division. The number 8 1/2 has units of miles. The number 1/4 has units of miles per day.
[tex]\dfrac{\text{miles}}{\left(\dfrac{\text{miles}}{\text{day}}\right)}=\dfrac{\text{miles}\cdot\text{day}}{\text{miles}}=\text{days}[/tex]
If you multiply, the product units are miles²/day. You cannot add or subtract numbers with different units. (They are not "like terms".)
As here, "units analysis" often tells you what math operations are needed, and which ones make no sense whatever.
