25(x-2y)平方-4(y-2x)平方答案是3(3x-4y)(x-8y)还是21(x-2y)2还是(7x-6y)有(3x-14y)

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25(x-2y)平方-4(y-2x)平方答案是3(3x-4y)(x-8y)还是21(x-2y)2还是(7x-6y)有(3x-14y)

25(x-2y)平方-4(y-2x)平方答案是3(3x-4y)(x-8y)还是21(x-2y)2还是(7x-6y)有(3x-14y)
25(x-2y)平方-4(y-2x)平方
答案是3(3x-4y)(x-8y)还是21(x-2y)2还是(7x-6y)有(3x-14y)

25(x-2y)平方-4(y-2x)平方答案是3(3x-4y)(x-8y)还是21(x-2y)2还是(7x-6y)有(3x-14y)
25(x-2y)平方-4(y-2x)平方
=【5(x-2y)+2(y-2x)][5(x-2y)-2(y-2x)]
=(x-8y)(9x-12y)
=3(3x-4y)(x-8y)

x五次方-x=x(x^4-1)=x(x^2+1)(x+1)(x-1)
9x四次方-36y平方=9(x^2+2y)(x^2-2y)
9(2a+b)平方-24(2a+b)(3a-b)+16(3a-b)平方
=[3(2a+b)]^2-2*[3(2a+b)]*[4(3a-b)]+[4(3a-b)]
=[3(2a+b)-4(3a-b)]^2
=(7b-6a)^2

全部展开

x五次方-x=x(x^4-1)=x(x^2+1)(x+1)(x-1)
9x四次方-36y平方=9(x^2+2y)(x^2-2y)
9(2a+b)平方-24(2a+b)(3a-b)+16(3a-b)平方
=[3(2a+b)]^2-2*[3(2a+b)]*[4(3a-b)]+[4(3a-b)]
=[3(2a+b)-4(3a-b)]^2
=(7b-6a)^2
x平方(4x-3y)+(3y-4x)=(x^2-1)(4x-3y)=(x+1)(x-1)(4x-3y)
x四次方-2x三次方-35x平方=x^2(x-7)(x+5)
25(x-2y)平方-4(2y-x)平方=21(x-2y)^2
x平方-4xy-1+4y平方=(x^2-4xy+4y^2)-1=(x-2y)^2-1=(x-2y+1)(x-2y-1)

收起

原式=[x-2y-2(y-2x)][x-2y十2(y-2x)]
=(5x-4y)(-3x)
=3x(4y-5x)

3(3x-4y)(x-8y)