Câu hỏi của Nguyễn Huyền Trang

Question

tìm các số gnuyeen x,y biết xy+x-2y +3 = 0

Nguyễn Lê Phước Thịnh · Accepted Answer

=>x(y+1)-2y-2+5=0

=>(x-2)(y+1)=-5

=>$\left(x-2;y+1\right)\in\left\{\left(1;-5\right);\left(-5;1\right);\left(-1;5\right);\left(5;-1\right)\right\}$

=>$\left(x,y\right)\in\left\{\left(3;-6\right);\left(-3;0\right);\left(1;4\right);\left(7;-2\right)\right\}$

Câu trả lời:

=>x(y+1)-2y-2+5=0

=>(x-2)(y+1)=-5

=>$\left(x-2;y+1\right)\in\left\{\left(1;-5\right);\left(-5;1\right);\left(-1;5\right);\left(5;-1\right)\right\}$

=>$\left(x,y\right)\in\left\{\left(3;-6\right);\left(-3;0\right);\left(1;4\right);\left(7;-2\right)\right\}$