Can you guys me with these math problems pls * 15 points*

Write the rational number in lowest terms 99/-15

Nikolas calculated the volume of the prism. his work is shown below.

Consider a cube that has sides of length l. now consider putting the largest sphere you can inside this cube without any point on the sphere lying outside of the cube. the volume ratio -volume of the sphere/ volume of the cube is 1. 5.2 × 10−1 2. 3.8 × 10−1 3. 1.9 4. 2.5 × 10−1 5. 3.8