Which of the following is equivalent to tan (5pi/6)? (Need help please)

Atoy company is considering a cube or sphere-shaped container for packaging a new product. the height of the cube would equal the diameter of the sphere . compare the volume to surface area ratios of the containers. which packaging will be more efficient? for a sphere, sa =4πr²

What expression is equivalent to 42x-56y

Can someone answer this question for me