c). {x- 2y + 6 = 0 x - 4 + 6 = 0 {4x + 7y - 6 = 0 x + 2 = 0 x = -2 {x-2y = -6 / . (-4) {4x + 7y = 6 -4x + 8y = 24 4x + 7y = 6 __________ 15y = 30 / :15 y = 2 d). {2(x-3)-y=4 {3(y+2)+2x=0 { 2x - 6 - y = 4 2x - 6 - 4 = 10 { 3y + 6 + 2x = 0 2x = 0 x = 0 { 2x - y = 10 / .(-1) { 2x + 3y = -6 {-2x + y = -10 { 2x + 3y = -6 ____________ 4y = -16 /: 4 y = -4 {x:2+y=4 5:2 + y =4 {x-y:3=1 y = 1.25 {x + y = 8 {x - y = 3 _________ 2x = 11 x = 5.5 f) {x+2/2 -y=3 {x-y-1/2=1 {x + 1 - y = 3 {x - y - 0.5 = 1 { x - y = 2 {x - y = 1.5 układ sprzeczny, nie ma rozwiązania :)
c) {x-2y+6=0 +{4x+7y-6=0 ___________ 5x+5y=0 x=-5y 5y-2y+6=0 3y+6=0 {y=-2 {x=10 d) {2(x-3)-y=4 {3(y+2)+2x=0 {2x-6-y=4 +{3y+6+2x=0 ___________ 4x+2y=4 x=1-1/2y 1-1/2y-6-y=4 { y=6 { x= -2
