Question

Giải hệ pt: \(\left\{{}\begin{matrix}0,3x+0,2y=0,5\\2x-\dfrac{1}{2}y=\dfrac{3}{2}\end{matrix}\right.\)

Answer 1

\(\left\{{}\begin{matrix}0,3x+0,2y=0,5\\2x-\dfrac{1}{2}y=\dfrac{3}{2}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}0,6x+0,4y=1\\0,6x-\dfrac{3}{20}y=\dfrac{9}{20}\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}\dfrac{11}{20}y=\dfrac{11}{20}\\2x-\dfrac{1}{2}y=\dfrac{3}{2}\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=\dfrac{11}{20}:\dfrac{11}{20}=1\\2x-\dfrac{1}{2}=\dfrac{3}{2}\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}y=1\\2x=\dfrac{3}{2}+\dfrac{1}{2}=2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}y=1\\x=\dfrac{2}{2}=1\end{matrix}\right.\)