Question

What are the excluded values of x for

Answer 1

x = - 2, x = 9

Explanation:

Given

f(x) =
`(x^2-9x)/(x^2-7x-18)`

The denominator of f(x) cannot be zero as this would make f(x) undefined.

Equating the denominator to zero and solving gives the values that x cannot be.

x² - 7x - 18 = 0

(x - 9)(x + 2) = 0

Equate each factor to zero and solve for x

x + 2 = 0 ⇒ x = - 2

x - 9 = 0 ⇒ x = 9

The excluded values are x = - 2, x = 9