==> x + 2 sqrt(x) sqrt(x+1) + x + #(x+1#) = 2x + 1 /**/
<=> 2 sqrt(x) sqrt(x+1) = 0 /**/
==> x = 0 \/ x+1 = 0 /**/
<=> x = 0 \/ x = -1
original <=> x = 0