Division by 0
Did you notice that the value of 2 will not work for a) and \(-3\) will not work for b) the values of 2 and\(-3\) make the denominators 0?
If not, remember that division by 0 is undefined since there is no number that can be multiplied by 0 that results in a product other than zero.
You may find some difficulty noticing that the value of 2 will not work for c) if you first factored the trinomial in the denominator.
Always keep in mind that the denominator can not be zero, and that the expression of a rational expression is undefined when the denominator is zero.