Question 983935
x = 16+sqrt(x)

x- sqrt(x) -16 = 0

y = sqrt(x)

y^2 - y -16 = 0

We'll only accept the positive solution since it would make sense that adding 16 to a square root will result positively.


{{{y = (1 + sqrt(1 - 4(-16))) / 2}}}

{{{ y = (1+sqrt(65))/2}}}

{{{sqrt(x) = (1+sqrt(65))/2}}}

{{{ x = ((1+sqrt(65))/2)^2 = 20.53}}}  <--- answer