(1)1.6x-1.4x=9.8
0.2x=9.8
x=9.8÷0.2
x=49
(2)(30.4-9.85)×1.06÷0.01
=20.55÷0.01×1.06
=2055×1.06
=2178.3
(3)0.99×1.02
=(1-0.01)×(1+0.02)
=1+0.02-0.01-0.0002
=1.0098