SOLUTION: identify all numbers for which rational expression is undefined r^3-6r / r^2-25

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Question 510145: identify all numbers for which rational expression is undefined r^3-6r / r^2-25
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
%28r%5E3-6r%29%2F%28r%5E2-25%29 This expression is undefined when the denominator equals zero, so set the denominator equal to zero and solve for r.
r%5E2-25+=+0 Add 25 to both sides.
r%5E2+=+25 Take the square root of both sides.
r+=+5 or r+=+-5
The expression is undefined for r = 5 and r = -5.