If theres a no solution in my equation of:

5x-4=4x+30+x then what do I write?

DNE ... does not exist

Remark

There's no ONE solution to this equation. But x can be anything or the solution could be the empty set. Try writing no solution. If that doesn't work, try empty set [which won't work if you don't know what a set is]. If that doesn't work, write your instructor or if you have notes, see what the notes say.