{7x+4y=43 6x-2y=26

{6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)= 3(x-y)把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)=3(x-y)²-4(x-y)+7(x-y)-6(x-y)²= {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 把(x-y)看做一个整体,合并同类项5(x-y)+2(x-y)-4(x-y)=3(x-y)次方-4(x-y)+7(x-y)-6(x-y)次方= (x-y)(x-2y)+(x-2y)(x-7y),其中X=4,Y=1.5 解二元一次方程{5X-2y=3 X+6y=7 {5x+4y=-3 2x-3y=8 {x+Y+Z=26 x-Y=1 2x-Y+z =18{x/3+Y/5=3 X/2- 2Y/5=1 快 1 .{5X-2y=3 X+6y=7 2.{5x+4y=-3 2x-3y=8 3.{x+Y+Z=26 x-Y=1 2x-Y+z =18 4.{x/3+Y/5=3 X/2- 2Y/5=1 初二上学期方程题 4x+y=5 5x+4y=63x-2y=1 2x+3y=13x-2y=7 7x+5y=32x+3y=17 2x-y=-4x+5y=6 2x+y=23x-6y=4 3x+2y=52x+y=73x-4y=53x+y=1x-2y=-1x+y=42x+3y=92x-3y=74x+5y=3x+y=20004x+6y=90003x+5y=113x-2y=42x+3y=215x-2y=5x+y=54x+3y=182x+3y=16x+4y=132x+3y=40x 大括号x+y/2+x-y/3=11/6 4(x+y)-5(x-y)=7 快 22.x+6y=14 3x+3y=27 23.7x+4y=67 2x+8y=26 2422.x+6y=14 3x+3y=27 23.7x+4y=67 2x+8y=26 24.5x+4y=52 7x+6y=74 4y-/2=-6x 2y 3x=7-2x-y 已知|5x-y-8|+(7y-x+2)=0则4x+6y