x方 y方等于多少
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原式=4x^(-6)y^6×(3x²y²)²=4x^(-6)y^6×9x^4y^4=36x^(-2)y^10=36y^10/x²
x*xy-4y=y(x^2-4)=y(x+2)(x-2)
(x+y)²=1x²+y²+2xy=1xy=-1(x+y)^3=x^3+y^3+3x^2y+3xy^2=x^3+y^3+3xy(x+y)x^3+y^3=(x+y)^3-3
(x-y)³×(x-y)²×(y-x)=(x-y)³×(x-y)²×[-(x-y)]=-(x-y)的6次方
x³+y³=(x+y)(x²-xy+y²)=x²-xy+y²=(x+y)²-3xy=1-3xy=1/3∴xy=2/9x五次方+y五
X^2-XY+Y^2=X^2-2XY+Y^2+XY=(X-Y)^2+XY再问:后面为什么要加xy?再答:为了前面利用公式(X-Y)^2=X^2-2XY+Y^2这是一个标准公式利用这个公式就好计算题目
25^x=80^y=2000∴25^(xy)=2000^y80^(xy)=2000^x上两式相乘得:2000^(xy)=2000^(x+y)∴xy=x+y得:1/x+1/y=1
直接将二式相乘,得(x²+ax+b)(3x+1)=3x³+x²+3ax²+ax+3bx+b=3x³+(1+3a)x²+(a+3b)x+b由于
解(x-y)(y-x)²(x-y)³=(x-y)(x-y)²(x-y)³=(x-y)^6
由(1)因式分(x+y)²-(x+y)³=(x+y)²(1-x-y)或者(2)计算:(x+y)²-(x+y)³=x²+2xy+y²
(x^4+y^4)(x^2+y^2)(x+y)(x-y)还原(x^4+y^4)(x^2+y^2)(x^2-y^2)(x^4+y^4)(x^4-y^4)x^8-y^8
(a)^3/2,(x/2y)^3/2且(x
x^3-y^3=x^3-x^2y+y^2x-yx^2+xy^2-y^3=x^2(x-y)+xy(y-x)+y^2(x-y)=(x-y)(x^2-xy+y^2)
(x+y)^3=x^3+3x^2y+3y^2x+y^3
(x-y)*(x^2+xy+y^2)
题目是不是(x^3+y^3)/(x+y)?应该等于x^2+xy+y^2
x方-y方+2x+1=(x^2+2x+1)-y^2=(x+1)^2-y^2=(x+y+1)(x-y+1)
-16x^4+81y^4=(9y^2-4x^2)(9y^2+4x^2)=(3y-2x)(3y+2x)(9y^2+4x^2)