What type of wave has more energy, an ultraviolet wave or an x-ray?

As the wave length increases the energy of the wave decreases as the equation that relates the c=λυ λ is the wave length and υ is the frequency (which is directly proportional to the energy).
In the wave length spectrum, x-ray has a shorter wave length, meaning that x-ray has a higher energy than ultraviolet waves.

Hope this helps.