Question in the screenshot, please help me

Find the value of the variable and the length of each secant segment

Which of the following quartic functions has x = –1 and x = –2 as its only two real zeroes?

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