Question

What are the excluded values of x for 2-3x-28/х2-2x-35

х= -7, x= 4
x=-7, х = 5
x=-5, х = 7
х= 4 х=7

Answer 1

C

Explanation:

The excluded values are the values of x that make the denominator of the rational function equal to zero as this would make the function undefined.

Equate the denominator to zero and solve for x to obtain the values that x cannot be.

x² - 2x - 35 = 0

(x - 7)(x + 5) = 0 ← in factored form

Equate each factor to zero and solve for x

x - 7 = 0 ⇒ x = 7

x + 5 = 0 ⇒ x = - 5

Excluded values of x are x = - 5, x = 7 → C