Question 678107
All real numbers except 0 and 4
...
{{{x^2-4x=0}}}
x(x-4)=0
x=0
AND
x-4=0
x=4
...
The equation has a whole, undefined area, where x = 0 and x = 4
Domain is 
(-{{{infinity}}}, 0) U (0, 4) U (4, {{{infinity}}})
...
{{{graph(300,200,-10,10,-10,10,(x+3)/(x^2-4x))}}}
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