a) {x+2y=-2 {2x-y=1 {x=-2y-2 -5y=5 y=-1 x=0 c){x-2y=3 {-2x+y=0 x=3+2y -3y=6 y=-2 x=-1 b){x+4y=-2 {3x-8y=10 x=-2-4y -20y=16 y=0,8 x=-5,2 d){2x+y=9 {5x-4y=3 y=9-2x 13x=39 x=3 y=3
a)x+2y=-2 2x-y=1 | razy 2 x+2y=-2 4x-2y=2 5x=0 x=0 y=-1 b) x+4y=-2 | razy -3 3x-8y=10 -3x-12y=6 3x-8y=10 -20y=16 |:-20 y=1,25 3x=20 |:3 x=0,15 c) x-2y=3 |razy 2 -2x+y=0 2x-4y=6 -2x+y=0 -3y=6 |:-3 y=-2 2x=-2|:2 x=-1 d)2x+y=9 |razy 4 5x-4y=3 8x+4y=36 5x-4y=3 13x=39|:13 x=3 y=9-6 y=3
a) {x+2y=-2 {2x-y=1 x=-2-2y 2(-2-2y)-y=1 -4-4y-y=1 -5y=5 y=-1 x=-2-2*(-1) x=-2+2 x=0 b) {x+4y=-2 {3x-8y=10 x=-2-4y 3(-2-4y)-8y=10 -6-12y-8y=10 -20y=16 y=-0,8 x=-2-4*(-0,8) x=-2+3,2 x=1,2 c) {x-2y=3 {-2x+y=0 x=3+2y -2(3+2y)+y=0 -6-4y+y=0 -3y=6 y=-2 x=3+2*(-2) x=3-4 x=-1 d) {2x+y=9 {5x-4y=3 y=9-2x 5x-4(9-2x)=3 5x-36+8x=3 13x=39 x=3 y=9-2*3 y=9-6 y=3
