a ) 2x-y=4 2x+y=4 sumujemy: _______________ 4x = 8 /:2 2x-y=4 x = 2 2*2-y = 4 /-4 x = 2 y = 0 b ) y-3x=6 y+3x=20-10-4 ______________ 2y = 12 /:2 y+3x = 6 y = 6 y+3x = 6 x = 0 y = 6 c) 2x+2y=3 2x-2y=4-1 ___________ 4x = 6 2x+2y=3 x = 1,5 2*1,5+2y=3 y = 0 x = 1,5 d) -3x+4y = 6 -3x-4y=6 ____________ -6x = 12 /:(-6) -3x+4y = 6 x = -2 -3*(-2)+4y = 6 x = -2 y = 0
a ) { 2x - y = 4 { 2x + y = 4 __________ 4x = 8 /:4 x = 2 2x + y = 4 2*2 + y = 4 4 + y = 4 y = 4 - 4 y = 0 { x = 2 { y = 0 b ) { y - 3x = 6 { y + 3x = 20 - 10 - 4 { y - 3x = 6 { y + 3x = 6 __________ 2y = 12 /:2 y = 6 y + 3x = 6 6 + 3x = 6 3x = 6 - 6 3x = 0 /:3 x = 0 { x = 0 { y = 6 c) { 2x + 2y = 3 { 2x - 2y = 4-1 { 2x + 2y = 3 { 2x - 2y = 3 ___________ 4x = 6 /:4 x = 1,5 2x + 2y = 3 2*1,5 + 2y = 3 3 + 2y = 3 2y = 3 - 3 2y = 0 /:2 y = 0 { x = 1,5 { y = 0 d) {- 3x + 4y = 6 {- 3x - 4y = 6 ____________ - 6x = 12 /:(- 6) x = - 2 - 3x + 4y = 6 - 3 * (- 2) + 4y = 6 6 + 4y = 6 4y = 6 - 6 4y = 0 /:4 y = 0 { x = - 2 { y = 0
