What is the following difference (adding and subtracting radicals - see attached)

Peaches cost $4.29 per pound. find the cost of two and a quarter pounds of peaches.

Look at attachment. has all info needed. need

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