问题
解答题
简算 ①9
②1.8×
③
|
答案
①9
-(32 5
+0.4),3 7
=9
-32 5
-0.4,3 7
=9
-2 5
-32 5
,3 7
=9-3
,3 7
=5
;4 7
②1.8×
+2.2×25%,1 4
=(1.8+2.2)×
,1 4
=4×
,1 4
=1;
③
×[0.75-(8 9
-7 16
)],1 4
=
×[0.75-8 9
+7 16
],1 4
=
×[8 9
+3 4
-1 4
],7 16
=
×(1-8 9
),7 16
=
×8 9
,9 16
=
.1 2