(9÷×-7)×0.6+1998=2010
(9÷×-7)×0.6=2010-1998
(9÷×-7)×0.6=12
9÷×-7=12÷0.6
9÷×-7=20
9÷x=20+7
9÷x=27
27x=9
x=1/3