Answer:
3rd option
Step-by-step explanation:
the denominator cannot be zero as this would make the expression undefined.
equating the denominator to zero and solving gives the values that x cannot be.
x² - 7x - 18 = 0 ← in standard form
(x - 9)(x + 2) = 0 ← in factored form
equate each factor to zero and solve for x
x - 9 = 0 ⇒ x = 9
x + 2 = 0 ⇒ x = - 2
then
x = - 2, x = 9 ← are the excluded values
