Question 103942: what values for x must be excluded in the following fraction
7 over
x-9
a. 0
b. -9
c. 9
d. none Found 2 solutions by doukungfoo, jim_thompson5910:Answer by doukungfoo(195) (Show Source):
You can put this solution on YOUR website! The answer is c. 9
the reason is if x is 9 the you have this:
And zero cannot be the denominator of a fraction, because you can't divide a number by zero.
Set the denominator equal to zero. Remember, dividing by 0 is undefined. So if we find values of x that make the denominator zero, then we must exclude them from the domain.
Add 9 to both sides
Combine like terms on the right side
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Answer:
So our answer is
Since makes the denominator equal to zero, this means we must exclude from our domain
So our domain is:
which in plain English reads: x is the set of all real numbers except
(