七分之四+八分之三+八分之一+七分之五

(1)4/7+3/8+1/8+5/7
=(4/7+5/7)+(3/8+1/8)
=9/7+1/2
=18/14+7/14
=25/14
(2)32/3-(3.14+2/3)
=32/3-2/3-3.14
=10-3.14
=6.86
(3)9/10+7/(5/12-1/8)
=9/10+7/(10/24-3/24)
=9/10+7/(7/24)
=9/10+24
=249/10
(4)9/10/(18×4/5-4/5)
=9/10/[(18-1)×4/5]
=9/10/(68/5）
=9/10×5/68
=18/68
=9/34
(5)0.4+2.6/(4.7-3.4)
=0.4+2.6/1.3
=0.4+2=2.4
（6）(2/69+2/71)×23+25/71
=2/3+46/71+25/71
=2/3+(46/71+25/71)
=2/3+1=5/3
(7)2.05-81/100/27×4.5
=2.05-3/100×4.5
=2.05-13.5/100
=2.5-0.135=2.365
(8)1.25×2.5×3.2
=(1.25×8)×(2.5×0.4)
=10+1=11

先去括号啊。。。