Question

(x+y)^2-3(x+y)-10

(a+b)^2-4a-4b+3
x^2y^2-5x^2y-6x^2
m^2-4mn+4n^2-3m+6n+2
x^2+4xy+4y^2-2x-4y-3
5(a+b)^2+23(a^2-b^2)-10(a-b)^2

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题目我不一一打上去了，就从我这些题目那里开始，他没给详细解答的麻烦帮我尽量多写一下，万分感谢！！

还有一题：a^2 x^2-6ax+8

快

Answer 1

令t=x+y
原式=t^2-3t-10=(t-5)(t+2)=(x+y-5)(x+y+2)

(a+b)的平方-4a-4b+3
＝(a+b)的平方-4（a+b）+3
＝（a+b-3）（a+b-1）

x^2y^2-5x^2y-6x^2
=x^2(y^2-5y-6)
=x^2(y-6)(y+1)

m^2-4mn+4n^2-3m+6n+2
=(m^2-4mn+4n^2)-(3m-6n)+2
=(m-2n)²-3(m-2n)+2
=(m-2n-1)(m-2n-2)

x^2+4xy+4y^2-2x-4y-3
=(x+2y)^-2(x+2y)-3
=(x+2y+1)(x+2y-3)

5(a+b)^2+23(a^2-b^2)-10(a-b)^2
=5(a+b)^2+23(a+b)(a-b)-10(a-b)^2
=[5(a+b)-2(a-b)]*[(a+b)+5(a-b)]
=(3a+7b)(6a-4b)
=2(3a+7b)(3a-2b)

补充完毕哈
【数学之美】很高兴为你解答，不懂请追问！满意请采纳，谢谢！O(∩_∩)O~

Answer 2

解：
(x+y)^2-3(x+y)-10
=(x+y-5)(x+y+2)

(a+b)^2-4a-4b+3
=(a+b)^2-4(a+b)+3
=(a+b-1)(a+b-3)

x^2y^2-5x^2y-6x^2
=x^2(y^2-5y-6)
=x^2(y-6)(y+1)

m^2-4mn+4n^2-3m+6n+2
=(m-2n)^2-3(m-2n)+2
=(m-2n-1)(m-2n-2)

x^2+4xy+4y^2-2x-4y-3
=(x+2y)^2-2(x+2y)-3
=(x+2y+1)(x+2y-3)

5(a+b)^2+23(a^2-b^2)-10(a-b)^2
=[5(a+b)-2(a-b)][(a+b)+5(a-b)]
=(3a+7b)(6a-4b)
=2(3a+7b)(3a-2b)

Answer 3

(x+y)^2-3(x+y)-10
=(x+y-5)(x+y+2)

(a+b)^2-4a-4b+3
=(a+b)^2-4(a+b)+3
=(a+b-1)(a+b-3)

x^2y^2-5x^2y-6x^2
=x^2(y^2-5y-6)
=x^2(y-6)(y+1)

不懂可追问
满意请采纳
谢谢

Answer 4

什么意思，没看懂，哪些是问题哪些是条件