Question

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

Answer 1

The excluded values of given expression are 5 and 7.

Explanation:

Given expression,

`(x^2-3x-28)/(x^2-2x-35)`

Excluded values are values that will make the denominator of a fraction equal to 0.

Here, the denominator =
`x^2-2x-35`

So, for excluded values,

`x^2-2x-35=0`

`x^2-7x+5x-35=0` ( By middle term splitting )

`x(x-7)+5(x-7)=0`

`(x+5)(x-7)=0`

If x + 5 = 0 ⇒ x = -5,

Or If x - 7 = 0 ⇒ x = 7,

Thus, the excluded values of given expression are 5 and 7.

Answer 2

-5 and +7

Explanation:

f(x) = (x²- 3x - 28)/(x² - 2x - 35)

The excluded values of x are those that make the denominator equal to zero.

x² - 2x – 35 =0

(x – 7)(x + 5) =0

x - 7 = 0

x = 7

x+ 5 = 0

x = -5

The excluded values of x are -5 and +7.