9（a+2b)²-4(a-b)² (x²+9y²）-36X²Y² 分解因式

9（a+2b)²-4(a-b)² (x²+9y²）-36X²Y² 分解因式
9（a+2b)²-4(a-b)² (x²+9y²）-36X²Y² 分解因式

9（a+2b)²-4(a-b)² (x²+9y²）-36X²Y² 分解因式
9(a+2b)^2-4(a-b)^2
=[3(a+2b)-2(a-b)][3(a+2b)+2(a-b)]
=(3a+6b-2a+2b)(3a+6b+2a-2b)
=(a+8b)(5a+4b)
(x^2+9y^2)^2-36x^2y^2
=(x^2+9y^2-6xy)(x^2+9y^2+6xy)
=(x-3y)^2(x+3y)^2

9（a+2b)²-4(a-b)²
=[3(a+2b)+2(a-b)]*[3(a+2b)-2(a-b)]
=(5a+4b)(a+8b)
(x²+9y²）²-36X²Y² (应该缺个²)
=(x²+9y²-6xy)(x²+9y²+6xy)
=(x-3y)²(x+3y)²

9(a²+4b²)-4(a²-b²)(x²+9y²)-36x²y²
=9a²+36b²-(4a²-4b²)(x²+9y²)-36x²y²
=9a²+36b²-[(4a²x²+36a&#...

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9(a²+4b²)-4(a²-b²)(x²+9y²)-36x²y²
=9a²+36b²-(4a²-4b²)(x²+9y²)-36x²y²
=9a²+36b²-[(4a²x²+36a²y²)-(4b²x²+36b²y²)-36x²y²
=9a²+36b²-(4a²x²+36a²y²-4b²x²-36b²y²)-36x²y²
=9a²+36b²-4a²x²-36a²y²+4b²x²+36b²y²-36x²y²
=(9-4x²36y²)a²+(36+4x²+36y²)b²-36x²y²

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