Question

观察下列各式:1平方+(1*2)平方+2平方=9=3平方

Answer 1

n²+[n(n+1)]²+(n+1)²=[n(n+1)+1]²

n²+[n(n+1)]²+(n+1)²

=n²+[n(n+1)]²+n²+2n+1 最后一项展开

=[n(n+1)]²+2(n²+n)+1

=[n(n+1)]²+2n(n+1)+1

=[n(n+1)+1]²

肯定是对的,我们数学老师讲的.