b) 3x + 2y = 2 + -3x + y = 10 ------------------------ 3y=12 y=4 3x+8=2 y=4 x=-2 y=4 c) 3x+2y =5 + 2x+2y =2 / *(-1) ------------------------------- x=3 9+2y=5 x=3 y=-2 d) x+4y =11 2x+5y =10 x=11-4y 2(11-4y)+5y=10 x=11-4y 22-8y+5y=10 x=11-4y -3y=-12 x=11-4y y=4 x=-5 y=4 e) 4x+5y =-4 / *(-6) 6x+7y =-6 / (4) -24x-30y=24 + 24x+28y=-24 ----------------------------- y=0 x=-1 f) 2x-11y =73 / *(-3) 3x-4y = 47 /*(2) -6x+33y=-219 + 6x-8y=94 ----------------- 25y=-125 y=-5 2x+55=73 y=-5 x=9 y=-5
b) 3x + 2y = 2 -3x + y = 10 3y = 12 / :3 y = 4 3x + 2 razy 4 = 2 y = 4 3x = 2 - 8 y = 4 3x = -6 / :3 y = 4 x = -2 c) 3x + 2y = 5 2x + 2 y = 2 / razy -1 3x + 2y = 5 -2x - 2y = -2 x = 3 3 razy 3 + 2y = 5 x = 3 2y = 5-9 x= 3 2y= -4 / :2 x= 3 y = -2 d) x + 4y = 11 / razy -2 2x + 5y = 10 -2x -8y = -22 2x + 5y = 10 - 3y = -12 / : -3 y = 4 x + 4razy4 = 11 y = 4 x= 11-16 y=4 x= -5 e) 4x + 5y = -4 / razy - 6 6x + 7y = -6 / razy 4 -24x - 30y = 24 24x +28y = -24 -2y = 0 / :-2 y = 0 4x + 0 = -4 y = 0 4x = -4 / :4 y=0 x= -1 f) 2x - 11y = 73 / razy - 3 3x - 4y = 47 / razy 2 -6x + 33y = - 219 6x - 8y = 94 25y = - 125 /: 25 y = -5 2x + 55 = 73 y= -5 2x= 18 y= -5 x= 9
b) 3x + 2y = 2 -3x + y = 10 -------------- 3y = 12 /:3 y = 4 3x + 2y = 2 3x + 2*4 = 2 3x + 8 = 2 / -8 3x = -6 / :3 x = -2 y = 4 x = -2 c) 3x+2y =5 2x+2y =2 / * (-1) 3x+2y =5 -2x -2y = -2 -------------- x = 3 3x+2y =5 3*3 +2y = 5 9 + 2y = 5 / -9 2y = -4 / :2 y = -2 x = 3 y = -2 d) x+4y =11 /*(-2) 2x+5y =10 -2x -8y = -22 2x + 5y = 10 ---------------- -3y = -12 / :(-3) y = 4 x+4y =11 x + 4*4 = 11 x + 16 = 11 /-16 x = -5 y = 4 x = -5 e) 4x+5y =-4 / *(-3) 6x+7y =-6 / *2) -12x - 15y = 12 12x + 14y = -12 ------------------ -y = 0 /*(-1) y = 0 4x+5y =-4 4x + 5*0 = -4 4x = -4 /:4 x = -1 y = 0 x = -1 f) 2x-11y =73 /*(-3) 3x-4y = 47 /*2 -6x + 33y = -219 6x - 8y = 94 ------------------- 25y = -125 /:25 y = -5 2x-11y =73 2x - 11*(-5) = 73 2x + 55 = 73 / -55 2x = 18 :2 x = 9 y = -5 x = 9
