`2x(y-5)=3y+4`
`2x(y-5)-3y=4`
`2x(y-5)-3y+15=19`
`2x(y-5)-3(y-5)=19`
`(y-5)(2x-3)=19`
ta có `19=19.1=(-1).(-19)`
$\begin{array}{|c|c|}\hline 2x-3&1&19&-1&-19\\\hline y-5&19&1&-19&-1\\\hline x&2&11&1&-8\\\hline y&24&6&-14&4\\\hline\end{array}$
`to(x;y)={(2;24);(11;6);(1;-14);(-8;4)}`