Answer:
C
Step-by-step explanation:
You know that one term has to be negative and the other has to be positive because -18 is negative (neg * pos = neg). You also know that the two terms have to sum up to 7! 9 and -2 fit the bill.
If you're not sure, you could always expand and check.
(x-2)(x+9)
x^2 -2x + 9x -18
x^2 +7x -18 (or, in this case, +7b)
Hope that helps!
