Find all real numbers for which the expression is underfined:

a.

b.

c.

d.

Strategy to find the real numbers for which each expression is undefined, we will find values of the variable that make the denominator 0.

Why We don?t need to examine the numerator of the rational expression; it can be any value, including 0. It?s a denominator of 0 that makes a rational expression undefined, because a denominator of 0 indicates division by 0.

7x x-5 3x - 2 9-x-x 8 +1 x + 9.4 12