(7/2+14/3)÷49/9-1.5
=(1/2+2/3)×7×9/49-1.5
=7/6×9/7-1.5
=1.5-1.5
=0
[2-(11.9-8.4×4/3)]÷1.3
=[2-(11.9-11.2)]÷1.3
=(2-0.7)÷1.3
=1.3÷1.3
=1
12-1÷4-1/4×7
=12-1/4-7/4
=12-(1/4+7/4)
=12-2
=10
200.8×10%+2.008×490+0.2008×5000
=20.08×1+20.08×49+20.08×50
=20.08×(1+49+50)
=20.08×100
=2008