Both of the right triangular prisms shown have bases that are right triangles with hypotenuse length 10 cm. One prism has height x and a base leg of length 6 cm. The other prism has height x - 2 cm and a base leg of length 5*sqrt(2) cm. The prism with height x - 2 cm has a volume that is 75% the volume of the prism of height x. What is the value of x?