5x+y=7 4x-3y=17

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= 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 （5x+3y)(3y-5x)-(4x-y)(4y+x)= 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 帮忙解一些方程组(1)3x-2y=6 2x+3y=17 (2)5x+6y=15.2 3x-2y=-0.4(3)2(x+y)-3y=7 4(x-9)=3(y-2)(4)3(x+y)-4(x-y)=4 x+y/2+x-y/6=1 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 已知:3x-5y=0,求x/y,x-y/y,x-y/x 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= 计算3x/(x-3y)+(x+y)/(4y-x)-7y/(x-4y)=? 大括号x+y/2+x-y/3=11/6 4(x+y)-5(x-y)=7 快 1.{5x=7y-1 5x=17-14y 2.{x=16-4y y=34-4x 3.{x+y=7 x:5=y:2 4.{x+2y=1 x-4y=-22 5.{3x=y+1/2 3x=y/4 1.{5x=7y-1 5x=17-14y 2.{x=16-4y y=34-4x 3.{x+y=7 x:5=y:2 4.{x+2y=1 x-4y=-22 5.{3x=y+1/2 3x=y/4 请解答方程组：（39）2x+y=5 (40)x+y=7 (41)2x+3y=12 (42)2x+y=3ax+3y=7 2x-y=8 3x+4y=17 3x-5y=11(43)3x+y=82 (44)3(x-1)=y+5 45 x/4+y/3=7 (46)x+y/3 +x-y/2=610x-11y=87 5(y-1)=3(x+5) 2/3x+y/2=14 3(x+y-)2(x-y)=28 x+y=5; x^y+y^x=17 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1