Question

a) 4x + y = 2;
{

    8x + 3y = 5

Answer 1

\(\left\{{}\begin{matrix}4x+y=2\\8x+3y=5\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}4.2+2y=2.2\\8x+3y=5\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}8x+2y=4\\8x+3y=5\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}-y=-1\\4x+y=2\end{matrix}\right.\\ \Rightarrow\left\{{}\begin{matrix}y=1\\4x+1=2\end{matrix}\right.\\ \Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{1}{4}\\y=1\end{matrix}\right.\)

Vậy \(\left(x;y\right)=\left(\dfrac{1}{4};1\right)\)

Answer 2

Đề là giải hệ phương trình hả em?