Question 382201: I hope someone can help me. I am suppose to: Which numbers can not be used in place of the variable in each rational expression? I need it worked out so I can understand it.
The problem is 2y+1/y^2-y-6
Thank you.
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Which numbers can not be used in place of the variable in each rational expression? I need it worked out so I can understand it.
The problem is 2y+1/y^2-y-6
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It's easier to see the values the variables cannot take
if you factor the rational expression.
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f(x) = (2y+1)/[(y-3)(y+2)]
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This expression cannot be evaluated if the denominator is zero.
So what values of y would make the denominator zero?
Solve: (y-3)(y+2) = 0
Since the product is zero, one, or both of the factors must be zero.
If y-3=0, y = 3
If y+2=0, y = -2
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So, if y = -2 or y=3 the denominator will be zero
and the rational expression will be meaningless.
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Answer: y = 3 or y = -2
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Cheers,
Stan H.
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