Question

Tìm x,y

a. yx - y - x² = 1

b. x² +xy=3x - y +1

Ai nhanh mình tick nhé !

Mình cảm ơn !

Answer 1

Hung nguyen giúp em nó với

Answer 2

Đề phải là x, y nguyên nhé.

a/ \(xy-y-x^2=1\)

\(\Leftrightarrow\left(xy-y\right)+\left(-x^2+1\right)=2\)

\(\Leftrightarrow\left(x-1\right)\left(y-x-1\right)=2\)

\(\Rightarrow\left(x-1,y-x-1\right)=\left(1,2;2,1;-1,-2;-2,-1\right)\)

Thế vô làm tiếp.

b/ \(x^2+xy=3x-y+1\)

\(\Leftrightarrow\left(xy+y\right)+\left(x^2-1\right)+\left(-3x-3\right)=-3\)

\(\Leftrightarrow y\left(x+1\right)+\left(x-1\right)\left(x+1\right)-3\left(x+1\right)=-3\)

\(\Leftrightarrow\left(x+1\right)\left(y+x-4\right)=-3\)

\(\Rightarrow\left(x+1,x+y-4\right)=\left(1,-3;-3,1;-1,3;3,-1\right)\)