a) 3s+5t=-6 1,5s-2t=-3t 3s+5t=-6 1,5s-2t=-3t /*(-2) 3s+5t=-6 -3s+4t=-6t 15t=6 /:15 t= 0,4 3s+5*0,6=-6 t= 0,4 3s=-3 /:3 s=1 t=0,4 b)5=3x-y 5x-2y=7 -3x=-y-5 5x-2y=7 -3x=-y-5 /*2 5x-2y=7 -6x=-2y-10 5x-2y=7 -x=-2y-10 /:(-1) 5x-2y=7 x=2y+10 5(2y+10)-2y=7 x=2y+10 10y+50-2y=7 x=2y+10 8y=-43 /:8 x=2y+10 y=5,375 x=2*5,375+10 y=5,375 x=10,75+10 y=5,375 x=20,75 y=5,375 c)x-3y=5 y+3x=-5 x-3y=5 /*(-3) y+3x=-5 -3x+9y=-15 y+3x=-5 10y=-20 /:10 y=-2 x-3y=5 y=-2 x-6=5 y=-2 x=11
a] 3s+5t=-6 3s+5t=-6 1,5s-2t=-3t |*(-2) -3s+4t=6t 3s+5t-3s+4t-6t=-6 <--3s i -3s skreśl ; ) 3t=-6 |:3 t=-2 3s+5*(-2)=-6 3s=-6+10 3s=4 |:3 s=3/4 t=-2 t=-2 t=-2 t=-2 b]5=3x-y |*(-2) -6x+2y=-10 5x-2y=7 5x-2y=7 -6x+2y+5x-2y=-10+7 <--2y i -2y skreśl -8y=-3 |:(-8) y=0,375 5x-2*0,375=7 5x=7+0,75 5x=7,75 |:5 x=1,55 y=0,375 y=0,375 y=0,375 y=0,375 c]x-3y=5 x-3y=5 y+3x=-5 |*3 3y+9x=-15 x-3y+3y+9x=5-15 <---3y i 3y skreśl 10x=-10 |:10 x=-1 -1-3y=5 -3y=5+1 -3y=6 |:(-3) y=-2 x=-1 x=-1 x=-1 x=-1
