擅长因式分解的高手帮下忙.-9x²y+3xyzx(y-z)-y(z-y)81x四次方-y的四次方m²

-9x²y+3xyz
=-3xy(3x-z)
x(y-z)-y(z-y)
=x(y-z)+y(y-z)
=(y-z)(x+y)
81x^4-y^4
=(9x^2+y^2)(9x^2-y^2)
=(9x^2+y^2)(3x^2+y)(3x^2-y)
m²+7m-18
(m-2)(m+9)
（x+y）²+2(y+x)+1
=(x+y+1)^2
121(a-b)²-169(a+b)²
=[11(a-b)]^2-[13(a+b)]^2
=(11a-11b+13a+13b)(11a-11b-13a-13b)
=(24a+2b)(-2a-24b)
=-4(12a+b)(a+12b)
5x²+6xy-8y²
=(x+2)(5x-4)
-a³-4a²+12a
=-a(a^2+4a-12)
=-a(a-2)(a+6)
(a²+4)²-16a²
=(a^2+4+4a)(a^2+4-4a)
=(a+2)^2*(a-2)^2
4x²(a-b)+16y²(b-a)
=4x^2(a-b)-16y^2(a-b)
=(a-b)(4x^2-16y^2)
=(a-b)(2x+4y)(2x-4y)
(x+1)(x+3)+1
=x^2+4x+3+1
=x^2+4x+4
=(x+2)^2
(x+y)²-4(x+y-1)
=(x+y)^2-4(x+y)^2+4
=(x+y-2)^2
计算.(-3)º+(-1/2)的-2次方÷2
=1+4/2
=3
3x²×（-3xy）²+(-2x)³×xy²
=3x^2*9x^2y^2-8x^3*xy^2
=27x^4y^2-8x^4y^2
=19x^4y^2
4(a-b)²-(2a+b)(-b+2a)
=4a^2+4b^2-8ab-4a^2+b^2
=5b^2-8ab
=b(5b-8a)
(x+y+2z)² (这个不是已经不能再分解因式了么,要求什么）
(a+2b-3c)(a-2b+3c)
(x+2y)(x-2y)-(x+2y)²+8y²
=（x+2y)(x-2y-x-2y)+8y^2
=-4y(x+2y)+8y^2
=4y(2y-x-2y)
(x+2y-3/2)(X+2y+3/2)
4-(a+2)(a-2)
=4-a^2+4
=8-a^2
(x²+y)(x²-y)-(-x²)×（-x²）
=x^4-y^2-x^4
=-y^2
(a+1)(4a-1)-(2a+1)(2a-1)
=4a^2+3a-1-4a^2+1
=3a
(a-2)(a+2)(a²+4)
=(a^2-4)(a^2+4)
=a^4-16
(3m²+5)(-3m²+5)-m²(7m+4)(7m-4)-16m²
=-9m^4+25-m^2*(49m^2-16)-16m^2
=-9m^4+25-49m^4+16m^2-16m^2
=-58m^4+25
简化,求值（2a-b）(b+2a)(b²+4a²).a=-1,b=-2
（2a-b）(b+2a)(b²+4a²).
=(4a^2-b^2)(4a^2+b^2)
=16a^4-b^4
=16-16
=0
已知(a+b)²=9,（a-b）²=49.a²+b²= 19 ,ab= -10
(a+b)^2=a^2+b^2+2ab=9
(a-b)^2=a^2+b^2-2ab=49
两式相加 a^2+b^2=58/2=29
两式相减 4ab=-40
ab=-10
解方程4(x-2)(x+5)-(2x-3)(2x+1)=5
4x^2+12x-40-4x^2+4x+3=5
16x=42
x=21/8
求2六次方+2的五次方+2的四次方+2³+2²+2+1的值和过程
设y=2^6+2^5+2^4+2^3+2+1
2y=2*(2^6+2^5+2^4+2^3+2+1)
=2^7+2^6+2^5+2^4+2^3+2
y=2y-y=2^7+2^6+2^5+2^4+2^3+2-(2^6+2^5+2^4+2^3+2+1)
=2^7-1
=127
2的2008次方+2的2007次方+2006次方+.+2²+2+1
设y=2的2008次方+2的2007次方+2006次方+.+2²+2+1
2y=2*(2的2008次方+2的2007次方+2006次方+.+2²+2+1)
=2的2009次方+2的2008次方+2的2007次方+2006次方+.+2²+2
y=2y-y=2的2009次方+2的2008次方+2的2007次方+2006次方+.+2²+2-(2的2008次方+2的2007次方+2006次方+.+2²+2+1)
=2^2009-1
^2009代表2009次方

-9x²y+3xyz=3xy（z-3x）
x(y-z)-y(z-y)=(y-z)(x+y)
81x四次方-y的四次方=(9x²+y²)(3x+y)(3x-y)
m²+7m-18=(m-9)(m+2)
（x+y）²+2(y+x)+1=（x+y+1）²
121(a-b)²-169(a+b)&#...

分太少了，付出和产出不成正比。