Let y = √(x - 10), so that y² = x - 10.
Then x = y² + 10 so that √x = ±√(y² + 10).
So we've rewritten the equation as
y = ±√(y² + 10)
In either case, squaring both sides gives
y² = y² + 10
and eliminating y² gives us the false result
0 = 10
so there is no solution.