Dr Sonnhard Graubner wrote:
hello, rewrite it in the form
$(x-1)^2-2007y^2=1$
and you will get a Pell equation.
Sonnhard.
yes it is pell equation $(x-1)^2-223(3y)^2=1$ but i dont think it is the way to solve it
minimal solution is $(x,y)=(225,5)$
We can write $x(x - 2) = 3^2 \cdot 223 \cdot y^2$, from which it follows that either $x$ is divisible by $223$ or $x - 2$ is divisible by $223$. Taking $x =223$ gives $x - 2 = 221$ which is not a perfect square. Taking $x - 2 = 223$, or $x = 225$ works; the corresponding value of $y$ is $5$.