(1)S=(3×4/2)×2=12
(3) (7 )7(7 )3
+ 3( 8)8(7 )
————————
(1 )1 6 6 0
(4) 305+x=3(95+x)∴x=10 补充(1) ( 0.01 )
( 0.04 ) (0.06 )
( 0.09 ) ( 0.08 )
( 0.03 )(0.05 )(0.07) (0.02 )