Question

算一算:1*2*3*4+1.3*4*5*6+1,4*5*6*7+1.想一想：你能发现什么规律?做一做：求11*12*13

Answer 1

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

=(n^2+3n)(n^2+3n+2)+1

=(n^2+3n+1)^2

所以原式=(11*11+3*11+1)^2=155^2=24025