若a(a-1)-(a*a-b)等于负二,求2a*a-5ab+3b*b+2a的值.谢啦,

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若a(a-1)-(a*a-b)等于负二,求2a*a-5ab+3b*b+2a的值.谢啦,
若a(a-1)-(a*a-b)等于负二,求2a*a-5ab+3b*b+2a的值.
谢啦,

若a(a-1)-(a*a-b)等于负二,求2a*a-5ab+3b*b+2a的值.谢啦,
a²-a-a²+b=-2
b-a=-2
a-b=2
2a²-5ab+3b²+2a
=(2a-3b)(a-b)+2a
=2(2a-3b)+2a
=4a-6b+2a
=6a-6b
=6(a-b)
=6×2
=12

a(a-1)-(a*a-b)=-2,则b=a-2
2a*a-5ab+3b*b+2a
=(a-b)(2a-3b)+2a
=2(6-a)+2a
=12

第一式化简有B=A-2
原式=2A*A-5A*B+3B*B+2A
把B 带入上式 有原式=2A*A-5*A*(A-2)+3(A-2)*(A-2)+2A
化简最后得 :12

由a(a-1)-(a*a-b)=-2得到b-a=-2
2a*a-5ab+3b*b+2a
=(2a*a-2ab+2a)+(3b*b-3ab)
=2a(a-b+1)+3b(b-a)
=6a-6b
=12