解x-y=50,y-70=3\5(x+70)+10

解这些方程组 (1) 7x-2y=96 5x-3y=45 (2) 4x+2y=50 2x+3y=47 (3) 4x+2y=66 7x-3y=70(4) 11x+9y=49 13x-3y=17 (5) 2y-x=1 13x-8y=59 (6) 18x+29y=307 16x+28y=284 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x 解方程组x+y/5+x-y/7=2 3(x+y)+x-y/7=16 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 解方程组3分之x-y=2分之 x+y解方程组3分之x-y=2分之 x+y；2x-5y=7 3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y怎么解 5(x-y)³-3（x-y）²+7(x-y)-5(x-y)³+（x-y）²-5（x-y）,其中,x-y=1/3.5(x-y)³-3（x-y）²+7(x-y)-5(x-y)³+（x-y）²-5（x-y）,其中,x-y=1/3先化简,再求值； 3x+5y-(x+y)=6 2(x+y)-3x=-7 x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x 1.解方程组{x+y=7,3x+y=172.{x+y=4,2x-y=53.{3x+2y=5x+2,2（3x+2y)=2x+8 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 证明：代数式[(x+y)(x-y)-(x+y)^2-2y(x-y)-2xy]/xy 的值为x,y的值无关 解方程 (x+1)^5/(-1-x)^4=3x+7一定要100%正确阿. 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= 解方程组{ (x-y)/3=(x+y)/2 { 2x-5x=7解方程组{ (x-y)/3=(x+y)/2{ 2x-5x=7{2x-5y=7 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 {80/(x+y) +42/(x-y) =7 40/(x+y) +70/(x-y) =7 怎么解( ⊙ o ⊙ {80/(x+y) +42/(x-y) =7 40/(x+y) +70/(x-y) =7 快 急