8a的四次方—2a²b²,-（x²-y²)(x+y)-(y-x)³,a的四次方-81b的四次方,因式分解

8a的四次方—2a²b²,-（x²-y²)(x+y)-(y-x)³,a的四次方-81b的四次方,因式分解
8a的四次方—2a²b²,-（x²-y²)(x+y)-(y-x)³,a的四次方-81b的四次方,因式分解

8a的四次方—2a²b²,-（x²-y²)(x+y)-(y-x)³,a的四次方-81b的四次方,因式分解
8a^4-2a²b²
=2a²(4a²-b²)
=2a²(2a+b)(2a-b)
-(x²-y²)(x+y)-(y-x)³
=-[(x+y)(x-y)](x+y)+(x-y)³
=-(x-y)(x+y)²+(x-y)³
=(x-y)[(x-y)²-(x+y)²]
=(x-y)[(x-y)+(x+y)][(x-y)-(x+y)]
=-4xy(x-y)
a^4-81b^4
=(a²+9b²)(a²-9b²)
=(a²+9b²)(a+3b)(a-3b)

8a的四次方—2a²b²
=2a^2(4a^2-b^2)
=2a^2(2a+b)(2a-b)

-（x²-y²)(x+y)-(y-x)³
=-(x-y)[(x+y)^2-(x-y)^2)
=-(x-y)(2y)(2x)
=4xy(y-x)

a的四次方-81b的四次
=(a^2+9b^2)(a^2-9b^2)
=(a^2+9b^2)(a+3b)(a-3b)

8a^4—2a²b²
=2a^2(4a^2-b^2)
=2a^2(2a+b)(2a-b)

-（x²-y²)(x+y)-(y-x)³
=-（x²-y²)(x+y)-[-(x+y)³]
=-（x²-y²)(x+y)+(x+y)³
=(...

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8a^4—2a²b²
=2a^2(4a^2-b^2)
=2a^2(2a+b)(2a-b)

-（x²-y²)(x+y)-(y-x)³
=-（x²-y²)(x+y)-[-(x+y)³]
=-（x²-y²)(x+y)+(x+y)³
=(x+y)³-（x-y)(x+y)²
=(x+y)²*[(x+y)-(x-y)]
=(x+y)²*2y
=2y(x+y)²

a^4-81b^4
=a^4-(3b)^4
=[a^2+(3b)^2]*[a^2-(3b)^2]
=(a^2+9b^2)*(a+3b)(a-3b)

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8a的四次方—2a²b²
=2a²[（2a）²-b²]
=2a²(2a-b)(2a+b)
-（x²-y²)(x+y)-(y-x)³
=-x³-x²y+xy²+y³-x³+3...

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8a的四次方—2a²b²
=2a²[（2a）²-b²]
=2a²(2a-b)(2a+b)
-（x²-y²)(x+y)-(y-x)³
=-x³-x²y+xy²+y³-x³+3x²y+3xy²-y³
=-x[x²-xy-(2y)²]
=-x(x-2y)(x+y)
a的四次方-81b的四次方
=[a²-(3b)²][a²+(3b)²]
=(a+3b)(a-3b)[a²+(3b)²]

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