The equation is undefined when x =:

The equation

is undefined when x =:
A . C9
B . C2
C . C6
D . 0
E . 9

Answer: A

Explanation:

An equation is undefined when the value of a denominator in the equation is equal to zero.

Set x 2 + 7 x C 18 equal to zero and factor the quadratic to find its roots:

x 2 + 7 x C 18

( x + 9) × ( x C 2) = 0

x = C9, x = 2