Question

计算，写过程！！！

急用，帮帮忙啊！！！！！

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Answer 1

(x+y)²(x-y)²(x²+y²)²=[(x+y)(x-y)]²(x²+y²)²=(x²-y²)²(x²+y²)²=[(x²-y²)(x²+y²)]²
=[x^4-y^4]²=x^8+y^8-2x^4y^4
(a+3b-2c)(a-3b+2c)=[a+(3b-2c)][a-(3b-2c)]=a²-(3b-2c)²
=a²-(9b²+4c²-12bc)=a²-9b²-4c²+12bc
(x-3y+1)(x+3y-1)-(x+3y)(x-3y)=[x-(3y-1)][x+(3y-1)]-(x+3y)(x-3y)
=[x²-(3y-1)²]-(x²-9y²)
=[x²-(9y²+1-6y)]-x²+9y²
=x²-9y²-1+6y-x²+9y²
=6y-1
[(a+b/2)²+(a-b/2)²]-(2a²-b²/2)=[(a²+4²/4+ab)+(a²+b²/4-ab)]-(2a²-b²/2)
=[2a²+b²/2]-(2a²-b²/2)
=b²
(x+y+z)(x-y-z)-(x+y-z)(x-y+z)=[x+(y+z)][x-(y+z)]-[x+(y-z)][x-(y-z)]
=x²-(y+z)²-[x²-(y-z)²]
=x²-(y²+z²+2yz)-[x²-(y²+z²-2yz)]
=x²-y²-z²-2yz-[x²-y²-z²+2yz]
=-4yz
(a+2b-c)(a-2b+c)-(a-2b-c)²=(a-2b-c+4b)(a-2b-c+2c)-(a-2b-c)²
=(a-2b-c)²+2c(a-2b-c)+4b(a-2b-c)+8bc-(a-2b-c)²
= 2c(a-2b-c)+4b(a-2b-c)+8bc
=2ac-4bc-2c²+4ab-8b²-4bc+8bc
=2ac+4ab-2c²-8b²