Help please I've been on this for an hour

Asystem of equation is shown below 6x - 2y equals 3 . and 5x + 3y equals 4. would you solve by substitution or elimination? and why

What is the difference between the points (4, 7) and (4, -5)? a. 0 units b. 2 units c. 4 units d. 12 units

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