Pls help asap

4 (2x + 3) = -3 (x - 1) +31

Just tell me how to set up the equation.

The volume of gas a balloon can hold varies directly as the cube of its radius. imagine a balloon with a radius of 3 inches can hold 81 cubic inches of gas. how many cubic inches of gas must be released to reduce the radius down to 2 inches?

Cone a has a surface area of 384 ft2 and cone b has a surface area of 96 ft? . what is the ratio of their volume?