Question

Решите пж срочно спасибо сразу (двумя способами)

Answer 1

$1) \ \ \left\{\begin{array}{l}3x+2y=9\\3x-y=1\end{array}\right\ \ominus \ \left\{\begin{array}{l}3y=8\\3x-y=1\end{array}\right\ \ \left\{\begin{array}{l}y=\dfrac{8}{3}\\3x-\dfrac{8}{3}=1\end{array}\right\ \ \left\{\begin{array}{l}y=\dfrac{8}{3}\\3x=\dfrac{11}{3}\end{array}\right\\\\\\\left\{\begin{array}{l}y=\dfrac{8}{3}\\\ x=\dfrac{11}{9} \end{array}\right\ \ \ Otvet:\ \ \Big(1\dfrac{2}{9}\, ;\, 2\dfrac{2}{3}\Big)\ .$

$2)\ \ \left\{\begin{array}{l}3x+2y=9\\3x-y=1\end{array}\right\ \ \left\{\begin{array}{l}3x+2(3x-1)=9\\y=3x-1\end{array}\right\ \ \left\{\begin{array}{l}3x+6x-2=9\\y=3x-1\end{array}\right\\\\\\\left\{\begin{array}{l}9x=11\\y=3x-1\end{array}\right\ \ \left\{\begin{array}{l}x=\dfrac{11}{9}\\y=3\cdot \dfrac{11}{9}-1\end{array}\right\ \ \left\{\begin{array}{l}x=\dfrac{11}{9}\\y=\dfrac{11}{3}-1\end{array}\right\ \ \left\{\begin{array}{l}\ x=\dfrac{11}{9}\\y=\dfrac{8}{3}\end{array}\right$

$Otvet:\ \ \Big(1\dfrac{2}{9}\, ;\, 2\dfrac{2}{3}\Big)\ .$