Question

7 класс,надо решить 2 системы​

Answer 1

Пошаговое объяснение:

$\left \{ {{8x+3y=31} \atop {6x-5y=45}} \right.$

$y=31-8x\\\\6x-5(31-8x)=45\\\\6x+40x=45+155\\\\x=200:46\\\\x=4\frac{8}{23}$

$\left \{ {{6(x-3)=7y-1} \atop {2(y+6)=3x+2}} \right.$

$x= \frac{7y-1}{6} +3\\\\2*(y+6)=(\frac{7y-1}{6} +3)*3+2\\\\2y+12= \frac{7y-1}{2}+11\\\\4y+24=7y-1+22\\\\7y-4y=21-24\\\\y=-1$