x3次方减y3次方加3x平方加3y平方减9x的极值-搜答案-神马作文网

x=3,y=3希望采纳

x²+3x-1=0x²+3x=1x³+5x²+5x+8=x³+3x²+2x²+5x+8=x(x²+3x)+2x²

x²-3x+1=0x²+1=3x两边平方x4次方+2x²+1=9x²x4次方+1=7x²两边平方x8次方+2x4次方+1=49x4次方x8次方+1=4

X3次方-3X

X³-3X=X(X²-3)=X(X+√3)(X-√3)

a^3+b^3=(a+b)(a^2-ab+b^2)a^3-b^3=(a-b)(a^2+ab+b^2)(x+y+z)^3-x^3-y^3-z^3=(y+z)[(x+y+z)^2+(x+y+z)x+x^2

很高兴喂你解答!原式=4√[(x^2+xy+y^2)/(x-y)*1/2√[(x^2-xy+y^2)/(x+y)*3√(x^3+y^3)=6√[(x^2+xy+y^2)/(x-y)*√[(x^2-xy

∵x+y+z=0,∴z=(-x-y)x^3+y^3+z^3=x^3+y^3-(x+y)^3=x^3+y^3-x^3-y^3-3x^2y-3xy^2=-3xy(x+y)=3xyz

x^3+y^3-x^2y-xy^2=x^2(x-y)-y^2(x-y)=(x^2-y^2)(x-y)=(x+y)(x-y)^2,因为x+y大于0,(x-y)^2大于等于0,所以x^3+y^3大于等于x

（9X平方Y3立方-12x3次方y平方）÷（3XY）=(9x²y^3-12x^3y²)/3xy=3xy²-4x²y=xy(3y-4x)请问前半部分是什么?再问：

X^4+X^3-4X^2+X+1=(X^4-2X^2+1)+X(X^2-2X+1)=(X^2-1)^2+X(X-1)^2=(X-1)^2(X-1)^2+X(X-1)^2=(X-1)^2[(X-1)^2

x的15次方+x的14次方加x的13次方加…加x的平方加x加1=(x+1)(x^14+x^12+x^10+x^8+x^6+x^4+x^2+1)=(x+1)(x^2+1)(x^12+x^8+x^4+1)

要求的式子=(x³－y³)＋(3xy²－x²y）－2（x²y－y³）=x³－y³＋3xy²－x²y－

^3代表3次方,^2代表平方X^3+X^2-Y^3-Y^2=(x^3-y^3)+(x^2-y^2)=(x-y)(x^2+xy+y^2)+(x-y)(x+y)=(x-y)(x^2+xy+y^2+x+y)

x3次方减4xy平方减2x平方y加8y三次方=x^2(x-2y)-(2y)^2(x-2y)=(x-2y)(x^2-(2y)^2)=(x+2y)(x-2y)^2

这是要立方和公式,x^3+y^3+3xy=(x+y)(x^2-xy+y^2)+3xy=x^2-xy+y^2+3xy=(x+y)^2=1

原式=（X^4-2^3)+(3X^3-6X^2)-(3X^2-6X)+(X-2)=X^3(X-2)+3X^2(X-2)-3X(X-2)+(X-2)=(X-2)(X^3+3X^2-3X+1)

不会诶

设x^4-x^3+4x^2+3x+5=(x^2+ax+1)(x^2+bx+5)=x^4+(a+b)x^3+(ab+b)x^2+(5a+b)x+5根据对应项系数相等,得a+b=-1①ab+b=4②5a+

x3次方-xy平方+x平方y-y3次方=x(x²-y²)+y(x²-y²)=(x+y)(x²-y²)=(x+y)(x+y)(x-y)=(x+