If f (x) is a continuous function defined for all real numbers, f (-10) = - 2, f (-8) = 5, and f (x) = 0 for one and only one value of x, then which of the following could be that x value?

-7

-9

0

2

F (-10) = - 2, f (-8) = 5, and f is continuous. All these mean that f (x) is 0 for x in between - 10 and - 8.

That is, f at - 10 is negative, then at - 8 is positive. So the graph of f "cuts" the x-axis for an x value in (-10, - 8).

Since there is only one value such that f (x) = 0, x can only be - 9.

Answer: - 9