Apiece of filter paper has an area of 12.5 cm2. which of these expressions shows the correct setup for converting this area to square millimeters (mm2)? what is the area of the filter paper in square millimeters?

We are given with the area of a filter paper in cm² and we need to convert this to mm². We can do this by dimensional analysis.
12.5 cm² x (10 mm / 1 cm)² = 1250 mm²
Notice that the ratio of the conversion between mm and cm is squared including the values and not just the units.

Hello there.

A piece of filter paper has an area of 12.5 cm2. Which of these expressions shows the correct setup for converting this area to square millimeters (mm2)? 

12.5 cm² x (10 mm / 1 cm)² = 1250 mm²

They are all solids.