①1718+2327-518-527；②89×[1516+（716-14）÷12]；③（2.8×1.8×4）÷（335×1.4×12）；④解方程：x-82%x=5.4．

Question

①(17)/(18)+(23)/(27)-(5)/(18)-(5)/(27)；                              
②(8)/(9)×[(15)/(16)+（(7)/(16)-(1)/(4)）÷(1)/(2)]；
③（2.8×1.8×4）÷（3(3)/(5)×1.4×(1)/(2)）；                 
④解方程：x-82%x=5.4．

Answer 1

①(17)/(18)+(23)/(27)-(5)/(18)-(5)/(27)
=(2)/(3)+(2)/(3)
=(4)/(3)；
                              
②(8)/(9)×[(15)/(16)+（(7)/(16)-(1)/(4)）÷(1)/(2)]
=(8)/(9)×[(15)/(16)+(3)/(16)×2]
=(8)/(9)×[(15)/(16)+(3)/(8)]
=(8)/(9)×(21)/(16)
=(7)/(6)；

③（2.8×1.8×4）÷（3(3)/(5)×1.4×(1)/(2)）
=2.8÷1.4×（1.8÷3(3)/(5)）×（4÷(1)/(2)）
=2×0.5×8
=8；                 

④x-82%x=5.4
   0.18x=5.4
       x=30．