Question

For what value(s) of x is the following expression undefined?

Answer 1

For the expression to be undefined, a value or values of x must make the denominator zero, since we can’t divide by zero.

To find those values of x, set the denominator equal to zero and solve.

x^2 + 5x - 36 = 0
(x + 9)(x - 4) = 0
x + 9 = 0
x = -9
x - 4 = 0
x = 4

Answer: The x values of -9 and 4 will make the expression undefined.