Question

when deciding which conversion factor to use be sure to select the conversion factor that will ____ the undesired units out. your answer

Explanation:

In unit - conversion, we use conversion factors to cancel out the units we don't want. For example, if we want to convert from miles to kilometers and we have a conversion factor $\frac{1.609\text{ km}}{1\text{ mile}}$, when we multiply a quantity in miles by this factor, the "miles" unit cancels out.

Answer:

cancel