(n+1)³-n³=3n²+3n+1n³-(n-1)³=3(n-1)²+3(n-1)+1……2³-1³=3*1²+3*1+1相加(n+1)³-1³=3(1²+2²+……+n²)+3(1+2+……+n)+1*n1+2+……+n=n(n+1)/...