-5(x-2y+1)-(1-3x+4y)
已知x-y=1,y≠0,求{(x+2y)²+(2x+y)(x+4y)-3(x+y)(x-y)}÷y的值.
先化简再求值:-3(2x-y)-{7-〔6x+2y-(10x-8y)〕+x-2(3x-4y)}已知x=-1/5,y=-5
计算:(1)2/(x+y)+4y/x²-y²(2)x²/x+y-x+y
[(2x+y)²-y(y+4x)-8x] ÷2x 其中x=2,y=-1
y=5;x=14;y=((x=3*y,x+6),x-1); printf(''x=%d,y=%d'
解方程组:(0.2x+0.1y)/2- (4x-y)/10=(x-y)/5+ (3x+0.5y)/30 (3x+2y-1
已知{(X的平方+Y的平方)-(X-Y)的差的平方+2Y(x-Y)}除以4Y=1
(x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3)
已知x+y=1,xy=-2分之1,利用因式分解求:x(x+y)(x-y)-x(x+y)²的值
3(x+y)-4(x-y)=11 2(x-y)+5(x+y)=27 解这个两元一次方程组
解下列二元一次方程{x+y/2+x-y/3=1 {4(x+y)-5(x-y)=2
用代入法解下列方程组:(1){y=x-3,y-2x=5; (2){x-3y=7,3x+