Question 721178
{{{x+5= sqrt(20x+9)}}}


square both sides

{{{(x+5)^2= 20x+9}}}

{{{x^2+10x+25=20x+9}}}


{{{x^2-10x+16=0}}}


{{{x^2-8x-2x+16=0}}}

{{{ x(x-8)-2(x-8)=0}}}

(x-8)(x-2)=0

x= 8 or 2