x ≠ - 4, 3
the denominator of the fraction cannot equal zero as this would make the fraction undefined. Equating the denominator to zero and solving gives the values that x cannot be
solve x² + x - 12 = 0
(x + 4)(x - 3) = 0
equate each factor to zero abd solve for x
x + 4 = 0 ⇒ x = - 4
x - 3 = 0 ⇒ x = 3
restrictions on x are : x ≠ - 4, 3
