\(\left\{{}\begin{matrix}0,3x+0,5y=3\\1,5x-2y=1,5\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}1,5x+2,5y=15\\1,5x-2y=1,5\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}4,5y=13,5\\1,5x-2y=1,5\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=3\\1,5x=2y+1,5=2\cdot3+1,5=7,5\end{matrix}\right.\)
=>\(\left\{{}\begin{matrix}x=5\\y=3\end{matrix}\right.\)
\(\left\{{}\begin{matrix}0,3x+0,5y=3\\1,5x-2y=1,5\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}1,5x+2,5y=15\\1,5x-2y=1,5\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}4,5y=-13,5\\1,5x-2y=1,5\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=\dfrac{-13,5}{4,5}=3\\1,5x-2.3=1,5\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}y=3\\x=\dfrac{1,5+6}{1,5}=5\end{matrix}\right.\\ Vậy:\left(x;y\right)=\left(5;3\right)\)
sao từ 1,5x+2,5y=15 tính ra 4.5y=-13,5 vậy ạ
