Question

Find alnumbers for which therational exprssion indefined 3^3-4m/m^2-81

Answer 1

Assuming I'm reading your expression correct, 3^3 - (4m)/(m^2) - 81...

...the only term you have to worry about is the 4m/(m^2) but note that the m in the numerator cancels out one of the power of m in the denominator so you have

3^3 - 4/m - 81

So the only place the expression is undefined is m = 0. Hope that helps!

Answer 2

begin with denominator equal zero - so because you know that one fraction than will be undefined sure
- so than ther will be (m-9)(m+9)=0
- so m-9=0 so m=9 and m+9=0 so m=-9

- than result that for m=+/- 9 this fraction will be undefined sure

Answer 3

hope that this will be understandably sure for you

good luck

bye

Answer 4

^ plugging 9 and -9 into the expression gives real numbers

3^3 - 4(9)/(9^2) - 81 = 9 - 36/81 - 81 = -652/9
3^3 - 4(-9)/(-9^2) - 81 = 9 + 36/81 - 81 = -644/9

The expression is only undefined when m=0.