下面各题,怎样算简便就怎样算. ①5/6×11+5/6 ②120+290÷58×16 ③(2/3-2/5)×(1/8+1/12) ④9/8÷[3/4-(7/16-1/4)].
问题描述:
下面各题,怎样算简便就怎样算.
①
×11+5 6
5 6
②120+290÷58×16
③(
-2 3
)×(2 5
+1 8
)1 12
④
÷[9 8
-(3 4
-7 16
)]. 1 4
答
①
×11+5 6
,5 6
=(11+1)×
,5 6
=12×
,5 6
=10;
②120+290÷58×16,
=120+290÷29÷2×16,
=120+5×16,
=120+80.
=200;
③(
-2 3
)×(2 5
+1 8
),1 12
=
×4 15
,5 24
=
;1 18
④
÷[9 8
-(3 4
-7 16
)],1 4
=
÷[9 8
+3 4
-1 4
],7 16
=
÷[1-9 8
],7 16
=
÷9 8
,9 16
=
×9 8
,16 9
=2.