Question 794412
{{{u=sqrt(x+4)}}}

{{{u=u^2}}}

{{{u^2-u=0}}}

{{{u(u-1)=0

{{{u=0}}}

or 

{{{u=1}}}


if {{{u=0}}}

then {{{x=-4}}}

if {{{u=1}}}

then
{{{x=-3}}}