8(x2-2y)-x(7x y) xy
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5x²-3xy-5y²-11xy-8x²+2y²=-3x²-3y²-14xy=-3(x²+y²)-14xy=-3x9+1
XY(XY-X^2)(X-Y)=X^2Y(X-Y)(X-Y)=(X-Y)(X^2Y-1)再问:答案是。-X2Y.我不知道过程是如何来的。能告诉我过程吗。谢谢。负X的平方Y
首先,X^2-XY+2Y^2=(X-2Y)(X+Y)所以,设x^2-xy-2y^2-x+5y-2可分解成(X-2Y+A)(X+Y+B)则展开有X的一次项=A+B=-1Y的一次项有A-2B=5连列成方程
x²+y-xy-x=﹙x²-xy﹚+﹙y-x﹚=x﹙x-y﹚-﹙x-y﹚=﹙x-y﹚﹙x-1﹚
X2+Y2+8X+6Y+25=0x²+8x+16+y²+6y+9=0(x+4)²+(y+3)²=0∴x+4=0y+3=0x=-4y=-3X2+4XY+4Y2分之
X2+Y2+8X+6Y+25=0x^2+y^2+8x+6y+25=0x^2+8x+16+y^2+6y+9=0(X+4)^2+(y+3)^2=0x=-4y=-3(x^2-4y^2)/(x^2+4xy+4
∵|x-y+1|与x2+8x+16互为相反数,∴|x-y+1|与(x+4)2互为相反数,即|x-y+1|+(x+4)2=0,∴x-y+1=0,x+4=0,解得x=-4,y=-3.当x=-4,y=-3时
x^2+xy-2y^2-x+7y-6=(x+2y)(x-y)-x+7y-6x+2y-3Xx-y2十字相乘得:2(x+2y)-3(x-y)=-x+7y是一次项所以原式=(x+2y-3)(x-y+2)
x2-2xy+y2+3x-3y+2=(x-y)2+3(x-y)+2=(x-y-1)(x-y-2).
分解因式有(x-3y)(2x-y)=0所以有x=3y或2x=y所以x:y=3:1或x:y=1:2
因式分解x²(x+1)-y(xy+x)原式=x³+x²-xy²-xy=x³-xy²+x²-xy=x(x²-y²
原式=8x2-16y2-7x2-xy+xy=x2-16y2=(x+4y)(x-4y).
解x+y=8两边平方(x+y)²=64即x²+2xy+y²=64∵xy=12∴x²+y²+24=64∴x²+y²=40(x-y)&
(x+y-2xy)(x+y-2)+(1+xy)2=(x+y)²-2(x+y)(xy+1)+4xy+(1+xy)²怀疑后面是(1-xy)²题目可能有问题(a2+9b2-1)
(-2x2次方y)乘(-三分之二xy)乘(-8xy)=-32/3X^(2+1+1)Y^(1+1+1)=-32/3*X^4Y^3
x^2-y^2=2xy,得x/y-y/x=2,即(y/x)^2+2(y/x)-1=0∴y/x=-1+√2或y/x=-1-√2(舍去,因为x,y都是正数).即(x-y)/(x+y)=√2-1
2x²+xy-3y²+x+4y-1=2×x×x+x×y-3×y×y+x+4×y-1=x×2x+x×y-y×3y+x×1+y×4-1=x×(2x+y+1)-y×(3y+4)-1再问:
原式=2x(x-y)4-x2(x-y)2+xy(x-y)2=x(x-y)2{2(x-y)2-x+y}=x(x-y)2{2(x-y)2-(x-y)}=x(x-y)3(2x-2y-1)
首先,X^2-XY+2Y^2=(X-2Y)(X+Y)所以,设x^2-xy-2y^2-x+5y-2可分解成(X-2Y+A)(X+Y+B)则展开有X的一次项=A+B=-1Y的一次项有A-2B=5连列成方程
49(x-2y-5)*2