For what value of x is the expression

x - 5/x² - 2x - 3

not defined?

daudallizzwell

12 years ago

For a fraction to be undefined, the denominator must be equal to 0.

Hence, we have:

x^2 - 2x - 3 = 0



Using factorization method, the factors of the which gives the sum (-2) and the product (-3) are -3 and +1.



Thus

x^2 - 3x + x - 3 = 0

x(x - 3) + 1(x - 3) = 0

(x + 1)(x - 3) = 0

If two products equal to 0, it means either

x + 1 = 0 or x - 3 = 0

Therefore

x = -1 or x = 3

timothy09

12 years ago

x=-1 or 3 aswer C