Question 499121
{{{sqrt(9x+64+8)=x}}}

{{{sqrt(9x+72)=x}}}

Take the square
9x+72=x^2
x^2-9x-72=0

Find the roots of the equation by quadratic formula					
					
a=	1	,b=	-9	c	-72
					
b^2-4ac=	81	-	288		
b^2-4ac=	369				
{{{sqrt(	369	)}}}=	19.21		
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}					
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}					
x1=(	9	+	19.21	)/	2
x1=	14.1				
x2=(	9	-19.21	) /	2	
x2= 	-5.105