rozwiąż układy równań: ⅔x+y-7=0 1⅓x+4y=⁷/₃ m+n/3 =5 3m+n/2=20-n/3 5(x-3y)=-7(3y-x) -3(x+4)+2(3-5y)=0

m+n/3 =5 3m+n/2=20-n/3 3m+n=15 18m+3n=120-2n 18m+5n=120 n=15-3m 18m+75-15m=120 3m=45 m=15 n=15-45=-30 5(x-3y)=-7(3y-x) -3(x+4)+2(3-5y)=0 6y=2x 3x+10y=6 x=3y 9y+10y=6 19y=6 y=6/19 x=18/19

⅔x+y-7=0 /x3 1⅓x+4y=⁷/₃/x 3 2x+3y-21=3 4x+12y=7 2x+3y=3+21/ x -2 4x+12y=7 -4x-6y=-48 4x+12y=7 6y=-41 y=-6,83 4x+12x-6,83=7 4x-81,96=7 4x=7+81,96 4x= 88,96 x=22,24 B)m+n/3 =5 /x 3 3m+n/2=20-n/3 /x 6 3m+n=15 18m+3n=40 - 2n 3m+n=15 /x -5 18m+5n=40 -15m-5n = -75 18m+5n =40 3m = -35 m = 11,66 3m+n=15 3 x 11,66 +n =15 34,98 +n = 15 n= 15 -34,98 n= - 19,98 C) 5(x-3y)=-7(3y-x) -3(x+4)+2(3-5y)=0 5x-15y = -21y+7x -3x-12+6-10y=0 5x-15y+21y-7x=0 -3x-10y=12-6 -2x+6y=0 / x - 3 -3x-10y=6/ x 2 6x-18y=0 -6x-20y=12 -38y=12 y=-0,31 -3x-10x - 0,31=6 -3x+3,1=6 -3x=6-3,1 -3x= 2,9 x=-0,96