Binomial expansion is a polynomial multiplication process. So the reduction you are talking about is actually a factorization of expansion. For example, the solution of factorization factor1+8x+28x 2+56x3+70x4+56x5+28x 6+8x7+x8: the original formula. (x+7x^2+2 1x^3+35x^4+35x^5+2 1x^6+7x^7+x^8)=( 1+7x+2 1x^2+35x^3+35x^4+2 1x^5+7x^6+x^7)+( 1+7x+2 1 x 2+35x 3+35x 4+2 1x 5+7x 6+x7)x =( 1+7x+2 1x。 Available: original formula = (1+x) (1+x) (1+x) (1+x) (65438)