SOLUTION: I have tried working this problem but can't figure out, please help. Which numbers cannot be used in place of the variable in each rational expression? 2x+3 ________

SOLUTION: I have tried working this problem but can't figure out, please help. Which numbers cannot be used in place of the variable in each rational expression? 2x+3 _________ x^2-16

Question 154856This question is from textbook elementary and intermediate algebra
: I have tried working this problem but can't figure out, please help. Which numbers cannot be used in place of the variable in each rational expression?
2x+3
_________
x^2-16
Thanks This question is from textbook elementary and intermediate algebra

Answer by scott8148(6628) (Show Source): You can put this solution on YOUR website!
usually, numbers which are not allowed are those which cause things to be undefinable

division by zero is the most common no-no

looking at the denominator of the fraction; if x^2 equals 16, then the denominator is zero

so, x can't be 4 or -4
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