Question 1085948
{{{f(x)=(x+1)/(-5x-10)}}}

denominator cannot be equal to zero, so exclude values that make {{{-5x-10=0}}}
{{{-10=5x}}}

{{{x=-10/5}}}

{{{x=-2}}}

domain:
{ {{{x}}} element {{{R}}} : {{{x<>-2}}} }



{{{f(x)=sqrt(4-x)}}}

{{{4-x=0}}}

{{{x=4}}}

domain:
{ {{{x}}} element{{{R}}}:{{{x<=4}}} }



{{{f(x)=(2-x)/(x^2-5x+6)}}}

{{{x^2-5x+6=0}}}

{{{x^2-2x-3x+6=0}}}

{{{(x^2-2x)-(3x-6)=0}}}

{{{x(x-2)-3(x-2)=0}}}

{{{(x-3)(x-2)=0}}}

{{{x=3}}} and {{{x=2}}}

domain:
{ {{{x}}} element {{{R}}} : {{{x<>2}}} and {{{x<>3}}} }