x-y=13 x=6y-7

x-y=13 x=6y-7 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 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 已知x+y=6,xy=7,试求x*x+y*y,x*x-y*y的值 已知：2x+y=6,x-3y=1 求7y(x-3y)(x-3y)-2(3y-x)(3y-x) x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x-y/13=y/7 x+y/y已知（x-y）/13=y/7则（X+Y）/Y=? 化简 x / y(x+y) - y / x(x+y) = 7x:4y,x:y=( ):( 3x+5y-(x+y)=6 2(x+y)-3x=-7 已知x^2+y^2+13-4x+6y=0,求(2x-y)^2-2(2x-y)(x+2y)+(x+2y)^2 (x-y)的4次方/(y-x)的3次方+(x-y)0的次方*(y-x)+(-x-y)7次方/(x+y)6次方= x(x+y)(x-y)-y(y+x)(y-x)=(x-y)( )填空 已知(x-y)/13=y/7,则（x+y）/y=已知x/6=y/4=z/3(x,y,z均不为零）,则(x+3y)/(3y-2z)= 1.（X-Y）/13=Y/7问（x+y）/y=?.2.x/6=y/4=z/3(x.z.y不为0)则（X+3Y）/3Y-2Z=? 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 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=