Question

Every problem has a solution change into negative sentence

Answer 1

I think its:
There is no problem without a solution.

Answer 2

Answer:  There is no problem without a solution.

Negative sentences are used when you are trying to convey which is false.

If you want to write a negative sentence in English then you just need to use ‘not’ word in the sentence.

Akash is not a happy person and Aisha doesn’t seem to be happy.

So after reading such negative sentences you can understand that they are stating that this statement is false.