一:2x-3y=7 二:x/2 - y-2/6=x+y/3 + 1
一:2x-3y=7 二:x/2 - y-2/6=x+y/3 + 1
解方程组一{2x-5y=1,5x+2y=17 二{x+y/2=6-x-y/3,4(x+y)-5(x-y)=2
一.x-y=2,则x²-2xy+y²= 二.x-y=-1,xy=3,则x³y-2x
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
求解;一 (x-8y)(x-y) 二 (Y+2)(Y-2)-(Y-1)(Y+5) 三 (3X+4)(3X-4)-(2X+
【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2=
一求方程组{6(x-y)-7(x+y)=21,2(x-y)-5(x+y)=-1的解二{2x-y-=-4,4x-5y=-2
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
解下列方程组:一.x=3y(1) 2x+y=7(2) 二.x=3y-5(1) 3y=8-2x(2) 三.x-2y=3(1