a) { 2x-2y=7/ *(-2) {4x+3y=21 {-4x+4y=-14 {4x+3y=21 7y=7/:7 y=1 2x-2=7 2x=9 x=4,5 b) {0,4x+0,3y=1,4/*(-10) {0,1x+3y=2,3 {-4x-3y=-14 {0,1x+3y=2,3 -3,9x=-11,7/:(-3,9) x=3 0,3+3y=2,3 3y=2 y=2/3 c){2x+3y=14/*(-3) {3x-2y=8/*2 {-6x-9y=-42 {6x-4y=16 -13y=-26 y=2 2x+6=14 2x=8 x=4 d){½x-2y=8/*(-4) {2x+5y=6 {-2x+8y=-32 {2x+5y=6 13y=-26 y=-2 2x-10=6 2x=16 x=8
a){2x-2y=7 |*(-2) {4x+3y=21 -4x+4y=-14 4x+3y=21 7y=7 y=1 2x-2y=7 2x-2=7 |+2 2x=9 x=4,5 b){0,4x+0,3y=1,4 |*(-10) {0,1x+3y=2,3 -4x-3y=-14 0,1x+3y=2,3 -3,9x=-11,7 x=3 0,1x+3y=2,3 0,3+3y=2,3 |-0,3 3x=2 x=2/3 c) {2x+3y=14 |*2 {3x-2y=8 |*3 4x+6y=28 9x-6y=24 13x=52 x=4 2x+3y=14 8+3y=14 |-8 3y=6 y=2 d) {½x-2y=8 |*(-4) {2x+5y=6 -2x+8y=-32 2x+5y=6 13y=-26 y=-2 2x+5y=6 2x-10=6 |+10 2x=16 x=8
{2x-2y=7 |*(-2) {4x+3y=21 -4x+4y=-14 4x+3y=21 7y=7 |/7 y=1 2x-2y=7 2x-2=7 |+2 x=4,5 y=1 b){0,4x+0,3y=1,4 |*(-10) {0,1x+3y=2,3 -4x-3y=-14 0,1x+3y=2,3 -3,9x=-11,7 x=3 0,1x+3y=2,3 |*10 x+30y=23 y=20/30=⅔ x=3 c) {2x+3y=14 |*2 {3x-2y=8 |*3 4x+6y=28 9x-6y=24 13x=52 |/13 x=4 2x+3y=14 8+3y=14 |-8 3y=6 |/3 y=2 x=4 y=2 d) {½x-2y=8 |*(-4) {2x+5y=6 -2x+8y=-32 2x+5y=6 13y=-26 |/13 y=-2 2x+5y=6 2x-10=6 |+10 2x=16 |/2 x=8 licze na naj
