Question

tìm x để

x (y+2) + y = 1

 

Answer 1

\(x\left(y+2\right)+y=1\)

\(\Rightarrow x\left(y+2\right)+y-1=0\)

\(\Rightarrow x\left(y+2\right)+y+2=3\)

\(\Rightarrow\left(x+1\right)\left(y+2\right)=3\)

Suy ra \(\begin{cases}x+1\\y+2\end{cases}\)\(\inƯ\left(3\right)=\left\{1;-1;3;-3\right\}\)

Xét \(x+1=1\Rightarrow x=0\Rightarrow y+2=3\Rightarrow y=-1\)Xét \(x+1=-1\Rightarrow x=-2\Rightarrow y+2=-3\Rightarrow y=-5\)Xét \(x+1=3\Rightarrow x=2\Rightarrow y+2=1\Rightarrow y=-1\)Xét \(x+1=-3\Rightarrow x=-4\Rightarrow y+2=-1\Rightarrow y=-3\)