7th grade math! I’ll brainlist! :)

Which value is not a solution of 8x^3 – 1 = 0

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

Which statement accurately describes how to perform a 90° clockwise rotation of point a (1,4) around the origin?