(9又2/7+7又2/9)除以(7/5+5/9)怎么简算

(9又2/7+7又2/9)除以(7/5+5/9)怎么简算
(9又2/7+7又2/9)除以(7/5+5/9)怎么简算

(9又2/7+7又2/9)除以(7/5+5/9)怎么简算
(5/7+5/9)吧
(9又2/7+7又2/9)除以(5/7+5/9)
=(65/7+65/9)/(5/7+5/9)
=13*(5/7+5/9)/(5/7+5/9)
=13

(65/7+65/9)/((63+25)/45)
=(65(9+7)/63)/(88/45)
=65*16*45/63*88
=65*90/63*11
=650/77