39*(9/13+7/11)+39/11
问题描述：
39*(9/13+7/11)+39/11
答
39*(9/13+7/11)+39/11
=27+39*7/11+39/11
=27+39/11（7+1）
=27+39*8/11
=27+（33+6）*8/11
=27+24+48/11
=55又4/11