Question

明天就考试了 那为大哥大姐会解啊

Answer 1

对,

n(n+1)(n+2)(n+3)+1

=[n(n+3)]*[(n+1)(n+2)]+1

=(n²+3n)(n²+3n+2)+1

=(n²+3n)²+2(n²+3n)+1

=(n²+3n+1)²