a) 2x+y-4=3(2x-y) 3(2x-3y)=2x+y-4 2x+y-4= 6x - 3y 6x -9y= 2x+y-4 4y= 6x-2x +4 /4 6x -9y= 2x+y-4 y= x+1 6x- 9(x+1)= 2x+ x+1 -4 y=x+1 6x- 9x - 9= 3x-3 y=x+1 6x-9x-3x= -3 +9 y=x+1 -6x= 6 y=x+1 x=1 x=1 y=2 2) 2x-(y-2)²=3-(y-1)(y+1) y- 2×-y/6 =½- 2y-×/4 2x - y2-4y +4= 3- (y2 -1) y- 2x - y/6= 1/2 -2y- x/4 /*12 2x-y2-4y+4= 3 - y2+1 12y- 24x- 2y= 6- 24y- 3x 2x-4y=3+1-4 12y- 24x- 2y= 6- 24y- 3x 2x= 4y 12y- 24x- 2y= 6- 24y- 3x x=2y 12y- 48y- 2y = 6-24y- 6y x=2y -8y= 6 x=2y y= -6/8 x=2y y=-0,75 x= -3/4 * 2= -3/2 y=-3/4 c) ⅖x-½y=2 / *10 ³/₄x+2y=6 /*4 4x-5y=20 3x+8y=24 4x=20+5y 3x+8y=24 x= 20+5y /4 3 (20+5y /4) +8y = 24 x=20+5y/4 60+15y/4 +8y= 24 x=20+5y/4 15+15y +8y=24 x=20+5y/4 23y=9 x=20+5y/4 y=9/23 x= 5+ 54/23 y=9/23
