cvxcb
幼苗
共回答了14个问题采纳率:100% 举报
(x+2)(x-2)+16
=x^2-4+16
=x^2+12
4(x+y)^2-20(x+y)+25
=(2x+2y-5)^2
a^2-b^2-4a+4b
=(a+b)(a-b)-4(a-b)
=(a-b)(a+b-4)
下面计算
(2+1)(2^2+1)(2^4+1)……(2^(2n)+1)
=(2-1)(2+1)(2^2+1)(2^4+1)……(2^(2n)+1)
=(2^2-1)(2^2+1)(2^4+1)……(2^(2n)+1)
=2^(4n)-1
1年前
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