rozwiąż układy równań a) y=-2x-1 x=y+7 b)4a+2b=10 5a-2b=-10 c)4(x-2)-(y-2)=1 10x-2y=18 d) 2x-4(y+1)=10 2(x+3)-(1-y)=9

a) x= -2x-1+7 x+2x=-1+7 3x=6/ :3 x=2 y=-2×2-1 y=-4-1 y=-5 x=2 y=-5 b 4a-2b=10/×(-1) 5a-2b=10 -4a+2b=-10 5a-2b=10 a=0 4×0-2b=10 -2b=10/:(-2) b=-5 a=0 b=-5 c)4(x-2)-(y-2)=1 10x-2y=18 4x-8-y+2=1/×(-2) 10x-2y=18 -8x+16+2y-4=-2 10x-2y=18 -8x+2y=-2-12 10x-2y=18 -8x+2y=-14 10x-2y=18 2x=4/:2 x=2 10×2-2y=18 20-2y=18 -2y=18-20 -2y=-2/:(-2) y=1 x=2 y=1 d 2x-4(y+1)=10 2(x+3)-(1-y)=9 2x-4y-4=10/×(-1) 2x+6-1+y=9 -2x+4y+4=-10 2x+6-1+y=9 -2x+4y=-10-4 2x+y=9-5 -2x+4y=-14 2x+y=4 5y=-10/:5 y=-2 2x-2=4 2x=4+2 2x=6/:2 x=3 y=-2