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1(x-3x-1)(x+3y-1)

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1(x-3x-1)(x+3y-1)
2(3x-2y+1/4)²
3(a+b)²-(a-b)²
4 [2x²-(x+y)(x-y)][(-x-y)×(y-x)+2y²],其中x=1 y=2
5[(0.5x-y)²+(0.5x+y)²](0.5x²-2y²)
6(a+3b)²-2(a+3b)(a-3b)+(a-3b)²
7(2a-b+c)²
写出来再加5分
1(x-3x-1)(x+3y-1)
1(x-3x-1)(x+3y-1)
=(x-1)²-9y²
=x²-2x-9y²+1
2(3x-2y+1/4)²
=9x²-12xy+3/2x+4x²-y+1/16
3(a+b)²-(a-b)²
=a²+2ab+b²+a²-2ab+b²
=2a²+2b²
4 [2x²-(x+y)(x-y)][(-x-y)×(y-x)+2y²],其中x=1 y=2
=(2x²-x²+y²)(-y²+x²+2x²)
=(x²+y²)(x²-y²)
=x四次-y四次方
=1-16
=-15
5[(0.5x-y)²+(0.5x+y)²](0.5x²-2y²)
=(0.5x²+2y²)(0.5x²-2y²)
=0.25四次方x-4y四次方
6(a+3b)²-2(a+3b)(a-3b)+(a-3b)²
=[(a+3b)-(a-3b)]²
=(6b)²
=36b²
7(2a-b+c)²
=4a²-4ab+4ac+b²-2bc+c²