Answer:
See attached image.
Explanation:
The explanations are on the attachment. The numerical results are below.
1. 63g/7cm^3 = 9 g/cm^3
2. The m or mm must be converted so that the units are the same. 1 m = 1000 mm. I'll convert the meters to mm: 0.080 m = 80 mm.
480 mm^2/80 mm = 6 mm
3. L times L makes no physical sense, unless this is a new Star Wars technique for making dark matter. Entertaining, but useless.
