PT(1) tuong duong: y^{2} + (y-3)x -4y+3=0 \Leftrightarrow (y-3)(y+x-1)=0 theo dk thi y=3 (loai) suy ra x+y-1=0 suy ra y=1-x thay vao (2) ta duoc:\sqrt[3]{x-2} + \sqrt{x+1} =3 ta dat : \left.\begin{matrix} \\ \end{matrix}\right\} \sqrt[3]{x-2} =t va \sqrt{x+1}=3-t dieu kien t\leq 2 ta binh phuong hai ve cua pt(3) va pt(4) rui lay ve tru ve taduoc ket qua t=1 thay vao pt(3) duoc x=3 cac ban tu lam nhe
PT(1) tuong duong
$y^{2} + (y-3)x -4y+3=0 \Leftrightarrow (y-3)(y+x-1)=0
$ theo dk thi y=3 (loai) suy ra
$ x+y-1=0
$ suy ra
$y=1-x
$ thay vao (2) ta duoc:
$\sqrt[3]{x-2} + \sqrt{x+1} =3
$ ta dat :
$\left.\begin{matrix} \\ \end{matrix}\right\} \sqrt[3]{x-2} =t
$ va
$\sqrt{x+1}=3-t
$ dieu kien
$t\leq 2
$ta binh phuong hai ve cua pt(3) va pt(4) rui lay ve tru ve ta
duoc ket qua t=1 thay vao pt(3) duoc x=3 cac ban tu lam nhe