The value of the surface area of a ractangular prism is equal to the value of the volume of the rectangular prism. write and solve an equation to find the value of x.

The rectangular prism has measures 6 units by 6 units by x units, 

Thus, the volume is 6*6*x = 36x (units cubed)

The surface area of the prism is

2(x*6+x*6+6*6)=2(6x+6x+36)=2(12x+36)=24x +72  (units squared.

36x=24x +72

36x-24x=72

12x=72

x=72/12=6

x=6