Question

Tìm x,y nguyên sao cho xy+2x-y+11=0

Answer 1

xy + 2x - y + 11 = 0

\(\Leftrightarrow\)(xy + 2x) + ( - y - 2) = - 13

\(\Leftrightarrow\)(y + 2)(x - 1) = -13

\(\Rightarrow\)(y + 2, x - 1) = (1, - 13; - 13, 1; - 1, 13; 13, - 1)

\(\Rightarrow\)(y, x) = (- 1, - 12; - 15, 2; - 3, 14; 11, 0)

Answer 2

xy+2x-y+11=0

<=>(xy+2x)+(-y-2)=-13

<=>(y+2)(x-1)=-13

=>(y+2,x-1)=(1;-13;-13;1;-1;13;13;-1)

=>(y;x)=(-1;-12;-15;2;-3;14;11;0)