2/9 ÷ 13/9 + 7/9 x 5/13
=2/9 x 9/13 +35/(9x13)
=2/13+35/(9x13)
【提取公因数1/13】
=(2+35/9)/13
=53/(9x13)
=53/117
2/9÷13/9+7/9×5/13
=2/9×9/13+7/9×5/13
=1/9×1/13×(2×9+7×5)
=1/9×1/13×53
=53/117
2/9÷13/9+7/9×5/3
=2/9×9/13+35/27
=2/13十1+8/27
=1+54/351+104/351
=1+158/351
=1又158/351
2/9÷13/9+7/9×5/13=2/9×9/13+7/9×5/13=2×9/9×13+7×5/9×13=2×9+7×5/9×13=18+35/(10-1)×13=53/117.