a) x+3y=3 x-y =5 x=3-3y 3-3y-y=5 -4y=2 y=-2 x=3-3*(-2) x=3+6 x=9 b) 2x-y=10 x+5y=-17 x=-17-5y 2(-17-5y)-y=10 -34-10y-y=10 -11y=44 y=-4 x=-17-5*(-4) x=-17+20 x=3 c) 3m+n=9 2m-5n=-11 n=9-3m 2m-5(9-3m)=-11 2m-45+15m=-11 17m=34 m=2 n=9-3*2 n=9-6 n=3 d) 4a-2=b 3a+7b=1,5 -b=-4a+2 b=4a-2 3a+7(4a-2)=1,5 3a+28a-14=1,5 31a=15,5 a=0,5 b=4*0,5-2 b=2-2 b=0 e) 5x=4-2y 4x=y -3 -y=-3-4x y=3+4x 5x=4-2(3+4x) 5x=4-6-8x 13x=-2 x=-2/13 y=3+4*(-2/13) y=3-8/13 y=31/13 f) 6x-3y=9 x+5y=-9,5 x=-9,5-5y 6(-9,5-5y)-3y=9 -57-30y-3y=9 -33y=66 y=-2 x=-9,5-5*(-2) x=-9,5+10 x=0,5
x+3y=3 x-y =5 1.) x=3-3y 3-3y-y=5 -4y=2 y=-0,5 x=3-3*(-0,5) x=3+1,5 x=4,5 x=4,5 y=-0,5 2.) 2x-y=10 x+5y=-17 2x-y=10 x=-17-5y 2(-17-5y)-y=10 x=-17-5y -34-10y-y=10 -11y=44 y=-4 x=-17-5*(-4) x=-17+20 x=3 x=3 y=-4 3.) 3m+n=9 2m-5n=-11 n=9-3m 2m-5(9-3m)=-11 2m-45+15m=-11 17m=34 m=2 n=9-3*2 n=9-6 n=3 m=2 n=3 4.) 4a-2=b 3a+7b=1,5 4a-2=b 3a+7(4a-2)=1,5 3a+28a-14=1,5 31a=15,5 a=2 b=4*2-2 b=6 a=2 b=6 5.) nie wiem, gdzie jest " = " w drugim równaniu 5x=4-2y 4x+y -3 6.) 6x-3y=9 x+5y=-9,5 6x-3y=9 x=-9,5-5y 6(-9,5-5y)-3y=9 -57-30y-3y=9 -33y=66 y=-2 x=-9,5-5*(-2) x=-9,5+10 x=0,5 x=0,5 y=-2
