Question

34x5y chia hết 36. tìm x,y?

Answer 1

\(\overline{34x5y}⋮36\)

\(\left\{{}\begin{matrix}36=4.9\\\left(4;9\right)=1\end{matrix}\right.\)

\(\overline{34x5y}⋮4\Leftrightarrow\left[{}\begin{matrix}y=2\\y=6\end{matrix}\right.\)

- Với \(y=2\)

\(\overline{34x52}⋮9\Leftrightarrow3+4+x+5+2⋮9\)

\(\Leftrightarrow x+14⋮9\)

\(\Leftrightarrow x=4\)

- Với \(y=6\)

\(\overline{34x56}⋮9\Leftrightarrow3+4+x+5+6⋮9\)

\(\Leftrightarrow x+18⋮9\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=9\end{matrix}\right.\)

Vậy \(\left(x;y\right)=\left\{\left(4;2\right);\left(0;6\right);\left(9;6\right)\right\}\) thỏa mãn đề bài