{2x+9y=-9 {-3x+3y=8 {2x+3y=4 {8x-5y=-1

{2x+9y=-9 {-3x+3y=8| *-3 {2x+9y=-9 {9x-9y=-24 ------------- {11x=-38|:11 {x= -3,8 {2*(-3,8)+9y=-9 {-7,2+9y=-9 {1,8y=-9|:1.8 {y=5 {2x+3y=4| *-4 {8x-5y=-1 {-8x-12y=-16 {8x-5y=-1 ------------ {-17y=-17|:-17 {x=1 2x+3y=4 2+3y=4 3y= 4-2 3y=2|;3 y=⅔

{2x+9y=-9 {-3x+3y=8 2x=-9-9y -3x+3y=8 x=-4,5-4,5y -3(-4,5-4,5y)+3y=8 x=-4,5-4,5y 13,5+13,5y+3y=8 x=-4,5-4,5y 16,5y=-8,5 x=-4,5-4,5y y=-0,5 ------------------ x=-4,5*2,25 x=-2,25 -----------------