SOLUTION: what real number(s) must be excluded from the domain of the given functions f(x)=x+1/-5x-10 f(x)=√4-x f(x)=2-x/x²-5x+6

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Question 1085948: what real number(s) must be excluded from the domain of the given functions
f(x)=x+1/-5x-10
f(x)=√4-x
f(x)=2-x/x²-5x+6
Answer by MathLover1(20849) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=%28x%2B1%29%2F%28-5x-10%29
denominator cannot be equal to zero, so exclude values that make -5x-10=0
-10=5x
x=-10%2F5
x=-2
domain:
{ x element R : x%3C%3E-2 }


f%28x%29=sqrt%284-x%29
4-x=0
x=4
domain:
{ x elementR:x%3C=4 }


f%28x%29=%282-x%29%2F%28x%5E2-5x%2B6%29
x%5E2-5x%2B6=0
x%5E2-2x-3x%2B6=0
%28x%5E2-2x%29-%283x-6%29=0
x%28x-2%29-3%28x-2%29=0
%28x-3%29%28x-2%29=0
x=3 and x=2
domain:
{ x element R : x%3C%3E2 and x%3C%3E3 }