Cистема уравнений 3х-2y=8 6x+3y=9 помогите срочно!

$\left \{ {{3x-2y=8} \atop {6x+3y=9}} \right.$

$\left \{ {{3x=8+2y} \atop {6x+3y=9}} \right.$

$\left \{ {{x=\frac{8+2y}{3}} \atop {6\cdot(\frac{8+2y}{3})+3y=9}} \right.$

$6\cdot(\frac{8+2y}{3})+3y=9$

$2(8+2y)+3y=9$

$16+4y+3y=9$

$16+7y=9$

$7y=9-16$

$7y=-7$

$y=-7:7$

$y=-1$

$x=\frac{8+2y}{3}=\frac{8+2\cdot(-1)}{3}=\frac{8-2}{3}=\frac{6}{3}=2$

$\left \{ {{x=2} \atop {y=-1}} \right.$

Проверка:

$\left \{ {{3\cdot2-2\cdot(-1)=8} \atop {6\cdot2+3\cdot(-1)=9}} \right.$

$\left \{ {{6+2=8} \atop {12-3=9}} \right.$

$\left \{ {{8=8} \atop {9=9}} \right.$