若(a+2)²+|b+1|=0,求(a-2b)²-(2a-b)(2a+b)+3a²+2的值
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若(a+2)²+|b+1|=0,求(a-2b)²-(2a-b)(2a+b)+3a²+2的值
若(a+2)²+|b+1|=0,求(a-2b)²-(2a-b)(2a+b)+3a²+2的值
若(a+2)²+|b+1|=0,求(a-2b)²-(2a-b)(2a+b)+3a²+2的值
∵(a+2)²+|b+1|=0
∴a+2=0;b+1=0(一个数的平方或绝对值一定大于等于0)
∴a=-2 ,b=-1
∴(a-2b)²-(2a-b)(2a+b)+3a²+2
=(a-2b)²-(4a²-b²)+3a²+2
=0-(16-1)+3×4+2
=-1