This is what I got when I put it in calculator. If u want whole number maybe you can take the decimals off of x.
Answer:
It is 18 because if you look at the side the small one says 3 the big one says 6 so if you multiply the 9 square feet by 2 thats your answer
The answer is going to be letter B
I'm guessing this is a quadratic equation xD
-4 and 10