3x+2y=13/razy (-2) 2x+y=11/razy 3 -6x-4y=-26 6x+3y=33 -y=7 y=-7 3x+2y=13 2x+y=11/razy(-2) 3x+2y=13 -4x-2y=-22 -x=-9 x=9 b) 5x+3y=0 -x-2y=7/ razy5 5x+3y=0 -5x-10y=35 -7y=35/ :(-7) y=-5 5x+3y=0/razy2 -x-2y=7/razy3 10x+6y=0 -3x-6y=21 7x=21/:7 x=3 c) 5=3x-y 5x-2y=7 3x-y=5/razy(-5) 5x-2y=7/razy 3 -15x+5y=-25 15x-6y=21 -y=-4 y=4 3x-y=5/razy(-2) 5x-2y=7 -6x+2y=-10 5x-2y=7 -x=-3 x=3 d) 3s+5t=-6 1,5s-2t=-3 /razy -2 3s+5t=-6 -3s+4t=6 9t=0 t=0 3s+5t=-6 / razy 2 1,5s-2t=-3 /razy 5 6s+10t=-12 7,5s-10t -15 1,5s=-27/:1,5 s=-18
w zalaczniku podpunkt b) poprawiony ( w załączniku matqq )
a) ( 3x + 2y = 13 ( 2x + y = 11 /*(-2) ( 3x + 2y = 13 ( -4x - 2y = -22 ______________ -x = -9 /*(-1) x = 9 2x + y = 11 2*9 + y = 11 18 + y = 11 y = 11 - 18 y = -7 ( x = 9 ( y = -7 b) ( 5x + 3y = 0 ( -x - 2y = 7 /*5 ( 5x + 3y = 0 ( -5x - 10y = 35 ______________ -7y = 35 /:(-7) y = -5 5x + 3y = 0 5x + 3*(-5) = 0 5x - 15 = 0 5x = 15 /:5 x = 3 ( x = 3 ( y = -5 c) ( 5 = 3x - y ( 5x - 2y = 7 ( -3x + y = - 5 /*2 ( 5x - 2y = 7 ( -6x + 2y = -10 ( 5x -2y = 7 _______________ -x = -3 /*(-1) x = 3 5x - 2y = 7 5*3 - 2y = 7 15 - 2y = 7 - 2y = 7 - 15 - 2y = - 8 /:(-2) y = 4 ( x = 3 ( y = 4 d) ( 3s + 5t = -6 ( 1,5s - 2t = -3 /*(-2) ( 3s + 5t = -6 ( -3s + 4t = 6 ____________ 9t = 0 /:9 t = 0 3s + 5t = -6 3s + 5*0 = -6 3s = -6 /:3 s = -2 ( s = -2 ( t = 0
