Question

2) 4x = -6y
7y - 2x = 20;
решите методом сложения плс​

Answer 1

Ответ:

$\left\{\begin{array}{l}4x=-6y\ |:2\\7y-2x=20\end{array}\right\ \ \left\{\begin{array}{l}2x+3y=0\\-2x+7y=20\end{array}\right\ \oplus \ \left\{\begin{array}{l}2x=-3y\\10y=20\end{array}\right\\\\\\\left\{\begin{array}{l}2x=-6\\y=2\end{array}\right\ \ \left\{\begin{array}{l}x=-3\\y=2\end{array}\right\\\\\\Ot et:\ \ (-3\, ;\, 2\, )\ .$