a) x + y = 6 x - y = 2 x=6-y 6-y-y=2 x=6-y 6-2y=2 x=6-y -2y=2-6 x=6-y -2y=-4 |:(-2) x=6-y y=2 x=6-2 y=2 x=4 y=2 b) x + y = 6 2x - y = 12 x=6-y 2(6-y)=12 x=6-y 12-2y=12 x=6-y -2y=12-12 x=6-y -2y=0 |:(-2) x=6-y y=0 x=6-0 y=0 x=6 y=0 c) 3 x + 2y = 4 1,5x + 6y = 12 |:1,5 3x+2y=4 x=8-4y 3(8-4y)+2y=4 x=8-4y 24-12y+2y=4 x=8-4y -10y=-20 |:(-10) x=8-4y y=2 x=8-4*2 y=2 x=8-8 y=2 x=0 d) 3x + 2y = 2 x - y = 4 3x+2y=2 x=4+y 3(4+y)+2y=2 x=4+y 12+3y+2y=2 x=4+y 5y=-10 |":5 x=4+y y=-2 x=4-2 y=-2 x=2 e) 2x - y = 16 x + 3y = 17 -y=-2x+16 |*(-1) x+3y=17 y=2x+16 x+3(2x+16)=17 y=2x+16 x+6x+48=17 y=2x+16 7x=-31 |:7 y=2x+16 x= -³¹/₇ y=2*(-³¹/₇)+16 x=-4³/₇ y=(-⁶²/₇)+16 x=-4³/₇ y= -8⁶/₇ + 16 x=-4³/₇ y=7¹/₇ x=-4³/₇
a) x + y = 6 x = 2 + y 2 + 2y = 6 2y = 6 - 2 2y = 4 y = 2 x + 2 = 6 x = 6 - 2 x = 4 b)x + y = 6 2x - y = 12 x = 6 - y 2 * (6 - y) + y = 6 12 - 3y = 6 -3y = -6 y = 2 x + 2 = 6 y = 4 c) 3 x + 2y = 4 1,5x + 6y = 12 1.5x = 12 - 6y x = 8 - 4y 3 * (8 - 4y) +2y = 4 24 + 2y = 4 2y = 4 - 24 2y = -20 y = -10 3x - 20 = 4 3x = 24 x = 8
