What is the area pls help​

Perform the indicated operation. 8/a - 6/a + 7/a

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 statements are true about additional information for proving that the triangles are congruent check all that apply