zadanie 1 x/2+y/3=1⅓ /*6 x/3-y/2=2⅓ /*6 3x+2y=8 /:3 2x-3y=14 x=2⅔ - ⅔y 2(2⅔- ⅔y)-3y=14 x=2⅔- ⅔y 5⅓- 1⅓ y- 3y=14 x=2⅔ - ⅔y 5⅓- 4⅓y=14 x=2⅔-⅔y -4⅓y=8⅔ /: (-4⅓) x=2⅔ - ⅔y y=-2 x=2⅔ - ⅔ * (-2) x=2⅔ + 1⅓ x=4 odp: x=4 y=-2 zadanie 2 0,6x+0,5y=2 0,5(2x-y)=2 0,6x+0,5y=2 x-0,5u=2 0,5y-0,5y=0 0,6x+x=2+2 0,5y-0,5y=0 1,6x= 4 / :1,6 0,5y-0,5y=0 x= 2,5 y=2(2-0,6x) y=4-1,2x y=4-3 y=1 odp: x=2,5 y=1 zadanie 3 (x+2)/5-2y=5 / *5 x-(y+2)/6=3 / *6 x+2-10y= 25 6x-y-2= 18 x-10y= 23 6x-y= 20 x=23+10y 6(23+10y)-y=20 x=23+10y 138+60y-y=20 x=23+10y 59y=-118 / :59 x=23+10y y=-2 x=23+(-2*10)=23-20=3 x=23-20 x=3 odp: x=3 y=-2 zadanie 4 (x+y)/2-x:3= 4 / *6 (x-y)/2+y:3= -3 /* 6 3x+3y-2x= 24 3x-3y+2y= -18 x+3y= 24 3x-y= -18 x=24-3y 3(24-3y) -y = -18 x=24-3y 72-9y=-18 x=24-3y 9y=90 / :9 x=24-3y y=10 x=24-30 x=6 odp: x=6 y=10 zadanie 5 (3x-1)/5+(2y-3)/4=(3y+3)/2 / *20 (x+y)/4-(3y-1)/2=(x-6y)/4 / *4 12x-4+10y-15= 30y+30 x+y-(6y-2)= x-6y 12x+10y-19= 30y+30 x+y-6y+2= x-6y 12x+10y-30y= 49 x-5y-x+6y= -2 12x-20y=49 y=-2 12x=49+20y y=-2 12x=49-40 12x=9 / :12 x=0,75 odp: x=0,75 y=-2 zadanie 6 (3x-2)/3-(2x+y)/6= x+⅙ / *6 x+y-(-x+y)/5= ⅕-0,8x / *5 6x-4-2x-y= 6x+1 5x+5y+x-y= 1-4x 4x-4-y= 6x+1 6x+4y= 1-4x -2x-y= 5 10x+4y= 1 y=- 2x-5 10x+4(-2x-5)= 1 y= -2x-5 10x-8x-20=1 y= -2x-5 2x=21 / :2 y= -2x-5 x= 10,5 y=-21-5 y=-26 odp: x=10,5 y=-26
