Cas.solve Problem

[megamanu]

Hi guys,

Im currently studying quantum physics, so i solve a lot of equations with very large or small numbers, like the speed of light, etc. The problem im having right now is, when i try to solve equations with the "solve" function in cas mode, the calculator shows me "two brackets" with nothing inside them, like an empty result, or sometimes the hp prime just crashes and restarts. Take for example this equation:
(i will also attached a photo of the equation just in case)
The solution must be 299999999.966 and the calculator shows me nothing. Can someone help me?