Question

试着说明:a(a+1)(a+2)(a+3)是一个完全平方式,请问怎样说明?

Answer 1

a(a+1)(a+2)(a+3)=[a(a+3)][(a+1)(a+2)]

=(a2+3a)(a2+2a+a+2)

=(a2+3a)(a2+3a+2)

=(a2+3a)(1+2)

=3(a2+3a)