Zad 1 a). {3x-5y=14 {2x+y= -8 / ·5 {3x-5y=14 +{10x+5y= -40 -------------------- 13x= -26 / : 13 x= -2 3x-5y=14 3·(-2)-5y=14 -6-5y=14 -5y=14+6 -5y=20 / :(-5) y= -4 {x= -2 {y=-4 b). {4m+5n= -11 {10n= -6m-24 {4m+5n= -11 / ·(-20 {6m+10n= -24 {-8m-10n=22 +{6m+10n= -24 ---------------------- -2m= -2 / :(-2) m=1 4m+5n= -11 4·1+5n= -11 5n= -11-4 5n= -15 / : 5 n= -3 {m=1 {n= -3 Zad4 a). {2x-3(y-1)=3(x-2y)+16 {3(5-x)-5y=3(y-2x)-21 {2x-3y+3=3x-6y+16 {15-3x-5y=3y-6x-21 {2x-3y-3x+6y=16-3 {-3x-5y-3y+6x= -21-15 {-x+3y=13 / · 3 {3x-8y= -36 {-3x+9y=39 +{3x-8y= -36 ----------------- y=3 -x+3y=13 -x+3·3=13 -x+9=13 -x=13-9 -x=4 / ·(-1) x= -4 {x= -4 {y=3 b). {y/3 +x/2 =1 / · 6 {x/3 - y/2 =5 / · 6 {2y+3x=6 {2x-3y=30 {3x+2y=6 / ·(-2) {2x-3y=30 / · 3 {-6x-4y= -12 +{6x-9y=90 ------------------- -13y=78 / :(-13) y=6 x/3 - 6/2=5 / · 6 2x-18=30 2x=30+18 2x=48 / : 2 x=24 {x=24 {y=6
