Rozwiąż metodą podstawiania 2x-4y=18 y=5x 3x+6y=12 x=-3y -3x+2y=1 x-y=3 x+y=9 x-y=-1 x+y=8 x-y=0

1) 2x-4*5x=18 -18x=18 x=-1 2) 3x+6y=12 x=-3y -9y+6y=12 -3Y=12 y= -4 3)-3x+2y=1 x-y=3 x=3+y -3(3+y)+2y=1 -9+3y=1 3y=10 y=3,333... 4)x+y=9 x-y=-1 x=-1+y -1+y+y=9 2y=8 y=4 5) x+y=8 x-y=0 x=y 2y=8 y=4

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

A) 2x-4y=18 y=5x 2x-4(5x)=18 y=5x 2x-20x=18 y=5x -18x=18/:(-18) y=5x x=-1 y=-5 B) 3x+6y=12 x=-3y 3(-3y)+6y=12 x=-3y -9y+6y=12 x=-3y -3y=12/:9(-3) x=-3y y=-4 x=-3*(-4) y=-4 x=-12 C)-3x+2y=1 x-y=3 -3x+2y=1 x=3+y -3(3+y)+2y=1 x=3+y -9-3y+2y=1 x=3+y -y=1+9 x=3+y -y=10/*(-1) x=3+y y=-10 x=3+(-10) y=-10 x=-7 D) x+y=9 x-y=-1 x+y=9 x=-1+y -1+y+y=9 x=-1+y 2y=9+1 x=-1+y 2y=10/:2 x=-1+y y=5 x=-1+5 y=5 x=4 D) x+y=8 x-y=0 x=8-y 8-y-y=0 x=8-y -2y=-8/:(-2) x=8-y y=4 x=8-4 y=4 y=4 x=4