9999 × 8889 + 3333 × 3333 + 9
= 9999 × 8889 + 9999 × 1111 + 9
= 9999 ×(8889 + 1111) + 9
= 9999 ×10000 + 9
= 99990000 + 9
= 99990009
参考http://zhidao.baidu.com/link?url=vTSSBBNYuiXf_N2ygvGthzY6YKkxkwa7BZJH4JuqpzNgnN8UOK9dbJmSXtzWZ0JqPrQ4r1DfyDN9Nf_u1orL8q