Question

tìm các số x, y: 3xy-4x+2y=1

giúp mik vs mik đg cần gấp

Answer 1

\(3xy-4x+2y=1\Rightarrow x\left(3y-4\right)=1-2y\Rightarrow x=\dfrac{1-2y}{3y-4}\)

-Vì x,y nguyên nên \(\left(1-2y\right)⋮\left(3y-4\right)\)

\(\Rightarrow\left(3-6y\right)⋮\left(3y-4\right)\)

\(\Rightarrow\left(-6y+8-5\right)⋮\left(3y-4\right)\)

\(\Rightarrow-5⋮\left(3y-4\right)\)

\(\Rightarrow3y-4\inƯ\left\{-5\right\}\)

\(\Rightarrow3y-4\in\left\{1;5;-1;-5\right\}\)

\(\Rightarrow y\in\left\{3;1\right\}\)

*\(y=1\Rightarrow x=\dfrac{1-2.1}{3.1-4}=1\)

*\(y=3\Rightarrow x==\dfrac{1-2.3}{3.3-4}=-1\)