HP Prime "Cannot Find Solution" when solving two equations

[Carsen]

Okay. I think the reason why you are getting an error message is because you have bad guess(es) entered in A, B, C, and/or X. The Solve App takes the current numbers assigned to the variables and uses them as guesses.

Enter 5's in A, B, C, and X. Then press solve. HP Prime should give you the correct answers with no troubles because you input better guesses.