Someone explain this/help me please

Ared balloon starts at 7.3 meters off the ground and rises at 2.6 meters per second. a blue balloon starts at 12.4 meters off the ground and rises at 1.5 meters per second. when will the balloons be at the same height?

The expression 6x2 gives the surface area of a cube, and the expression x3 gives the volume of a cube, where x is the length of one side of the cube. find the surface area and the volume of a cube with a side length of 6m

For each proportion find the unknown number x 1/5/8=×/15