A) 2x - 3y = 7/*(-3) 3x - 5y = 11/*2 -6+9y=-21 6x-10y=22 ----------------- -6+9y+6x-10y=-21+22 -1y=1/*(-1) y=-1 6x-10*(-1)=22 6x+10=22 6x=22-10 6x=12/:6 x=2 y=-1 b) 5p - 2r = 21/*5 3p + 5r = -6/*2 25p-10r=105 6p+10r=-12 ------------------- 25p-10r+6p+10r=105-12 31p=93/:31 p=3 6*3+10r=-12 18+10r=-12 10r=-12-18 10r=-30:/10 r=-3 p=3 c) 2x - 3y = 10/*5 5x + 5y = 0/*3 10x-15y=50 15x+15y=0 ----------------------- 10x-15y+15x+15y=50 25x=50/:25 x=2 10*2-15y=50 20-15y=50 -15y=30/:(-15) y=-2 x=2 liczę na najlepszą :P pozdrawiam :)
a) 2x - 3y = 7 / * 5 3x - 5y = 11 / * (-3) 10x - 15y = 35 -9x + 15y = -33 x=2 x =2 10*2 - 15y =35 x=2 -15y=35-20 x=2 -15y=15 / : (-15) x=2 y= -1 b) 5p - 2r = 21 / * 5 3p + 5r = -6 / * 2 25p -10r = 105 6p +10r = -12 31p = 93 /: 31 p = 3 p=3 6*3 +10r = -12 p=3 10r= -12 - 18 p=3 10r= -30 / : 10 p=3 r= -3 c) 2x - 3y = 10 / * 5 5x + 5y = 0 / * 3 10x - 15y= 50 15x + 15y= 0 25x=50 / :25 x=2 x=2 5*2+5y=0 x=2 5y= - 10 / :5 x=2 y= -2
A) 2x - 3y = 7/ *-³/₂ 3x - 5y = 11 -3x+4,5 y=-10,5 3x - 5y = 11 -1,5y=1,5 y=-1 x=2 B) 5p - 2r = 21/*2,5 3p + 5r = -6 12,5p-5r=52,5 3p + 5r = -6 15,5p=46,5 p=3 r=-3 C) 2x - 3y = 10/*-2,5 5x + 5y = 0 -5x+7,5y=-25 5x + 5y = 0 12,5y=-25 y=-2 x=2
