My father had a trouble with his lungs, ___ he decided to give up smoking

A. so that B. so C. since D.though

\(\left\{{}\begin{matrix}4x-3y=19\\2x+3y=11\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}6x=30\\2x+3y=11\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=5\\2.5+3y=11\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}x=5\\10+3y=11\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=5\\3y=1\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=5\\y=\dfrac{1}{3}\end{matrix}\right.\)

Vậy (x;y)=\(\left(5;\dfrac{1}{3}\right)\)

CTVVIP là sao????