Well I didn't ask if it was wrong; I asked if it makes sense. Not exactly the same thing. It's nice to have the answer ahead of time for checking if you did the problem right, but this will not always be the case. It's good to develop an understanding of whether an answer makes sense. This is a quick and easy way to determine if your answer is likely to be incorrect. Your answer (positive root, 0.089) can't possibly be right, because if it was, your equilibrium concentration of RP would be negative, which is impossible.
Now, how do we troubleshoot where you went wrong? Here's an idea. Take your root, 0.089, and put it back in your quadratic equation. Does the right hand side equal zero? If yes, you know you solved the quadratic equation correctly, and it is likely your table is wrong. If no, you know you've made some algebra mistake when solving your equation. This doesn't mean your table is necessarily right (you could make mistakes in more than one place), but I'm trying to teach you how to troubleshoot your own wrong answers and find out where you went astray.