先化简再求值x y分之x的平方-y的平方
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![先化简再求值x y分之x的平方-y的平方](/uploads/image/f/2039969-65-9.jpg?t=%E5%85%88%E5%8C%96%E7%AE%80%E5%86%8D%E6%B1%82%E5%80%BCx+y%E5%88%86%E4%B9%8Bx%E7%9A%84%E5%B9%B3%E6%96%B9-y%E7%9A%84%E5%B9%B3%E6%96%B9)
解3x平方y-[2xy-2(xy-3/2x平方y)+xy]=3x平方y-(2xy-2xy+3x平方y+xy)=3x平方y-(xy+3x平方y)=3x平方y-3x平方y-xy=-xy=-3×(-1/3)
所求之数值是1.[(xy+2)(xy-2)-(xy+2)²+8]÷(2x)={(xy+2)[(xy-2)-(xy+2)]+8}/(2x)=[(xy+2)(xy-2-xy-2)+8]/(2x)
xy=1x^2+y^2=6x+y=2sqr(2)y-x=2注意后面那个分数是等于-1.最后强算就是了,最后那个分母有理化稍微有点复杂,我就不算了.
(xy-x的平方)除以xy分之x的平方-2xy+y的平方乘x的平方分之x-y=x(y-x)*xy/(x-y)²*(x-y)/x²=-y再问:不好意思,打错了(xy-y的平方)除以x
(xy-x²)÷(x²-2xy+y²)/(x-y)×(x-y)/x²=-x(x-y)÷(x-y)²/x²=-x(x-y)×x²/(
x的平方-y的平方分之x的平方+2xy+y的平方除一x-y分之x的平方+xy,其中x=√2-1,y=√2+1=(x+y)^2/(x+y)(x-y)/((x^2+xy)/(x-y))=(x+y)/(x-
y的平方-xy分之(x+y)的平方÷{-(x-y)的平方分之y的平方+xy}=(x+y)²/[y(y-x)]÷[-y(y+x)/(x-y)²]=(x+y)²/[y(x-y
2xy²-x²y-3分之1(-3x²y-6xy²)=2xy²-x²y+xy²+2x²y=3xy²+x²
原式=(9x³-xy²)/[(3x+y)(9x²-6xy+y²)]=x(9x²-y²)/[(3x+y)(3x-y)²]=x(3x+
5x²-(3y²+5x²)-(4x²+7xy)=5x²-3y²-5x-²4x²-7xy=-4x²-3y
/>原式=[(x²-2xy+y²)/(x²-xy)]÷(x/y-y/x)={(x-y)²/[x(x-y)]}÷[(x²-y²)/(xy)]=
分子分母同乘以4.再一化简
先化简,再求值:3X的平方-{2X的平方-(2XY-X的平方)+4XY},其中X=2,Y=-4分之3:3X的平方-{2X的平方-(2XY-X的平方)+4XY},=3X的平方-2X的平方+(2XY-X的
2分之1x的平方y-3分之1xy-0.5x的平方y+0.5xy=6分之1xy=6分之1*3*(-2)=-1
(3x²-xy)/(9x²-6xy+y²)=x(3x-y)/(3x-y)²=x/(3x-y)带值;=2/(6-3)=2/3
(1)(x²-y²)/(x²-2xy+y²)=(x-y)(x+y)/(x-y)²=(x+y)/(x-y)x²+y²-2x-6y+1
[(xy+2)(xy—2)—2(x的平方y的平方—2)]=x²y²-4-2x²y²+4=-x²y²;很高兴为您解答,skyhunter002
解(y²-xy)/(x²-y²)=y(y-x)/(x+y)(x-y)=-y/(x+y)(2x²-2y²)/(x²+2xy+y²)=