解7/9÷14/15+7/9 X 15/14=7/9×15/14+7/9 X 15/14=2×7/9×15/14=14/9×15/14=15/9=5/3
= 7/9× 15/14 + 7/9× 15/14 =(7/9+7/9)× 15/14 = 14/9 × 15/14 =15/9 有疑问请追问
7/9÷14/15+7/9 X 15/14=7/9×15/14+7/9 X 15/14=7/9×(15/14+15/14)=7/9×15/7=5/3