(1)9.07-22.78÷1.7
=9.07-13.4
=-4.33
(2)1.05÷0.7+18.9
=1.5+18.9
=20.4
(3)21.5÷0.05×0.96
=430×0.96
=412.8
(4)0.4×5÷0.4×5
=0.4÷0.4×5×5
=1×5×5
=25
(5)(7.5-2.3×0.4)÷0.01
=(7.5-0.92)÷0.01
=6.58÷0.01
=658
(6)10÷4÷12.5
=10÷(4×12.5)
=10÷50
=0.2
(7)1800÷12.5÷2.5÷(0.8×4)
=1800÷12.5÷2.5÷0.8÷4
=1800÷(12.5×0.8)÷(2.5×4)
=1800÷10÷10
=18