Đk:..........
\(\left(1\right)\Leftrightarrow y^2-x^2=2y\sqrt{x-1}-\left(x-1\right)\)
\(\Leftrightarrow y^2-2y\sqrt{x-1}+\left(x-1\right)=x^2\)
\(\Leftrightarrow\left(y-\sqrt{x-1}\right)^2=x^2\)
\(\Leftrightarrow\left(y-\sqrt{x-1}+x\right)\left(y-\sqrt{x-1}-x\right)=0\)
rồi tự làm tiếp nha