Check out slader.com if this is a textbook problem
answer (0,10) see pic:
This is the 3rd one I have helped with, you should start seeing a pattern with the answers.
I'm not going to give you the answer, but I can try to help you. A common denominator, I think, is like when you try to find out the number they all multiply. Like, for example, 9. 1, 3, 9, etc. are numbers you can use to either multiply up to 9, or more than 9. I don't know if I even make sense. Just do a good amount of research.
Answer: 7
Step-by-step explanation: