问题
解答题
计算下列各题.(能简算的写出简算过程)
|
答案
(1)
+1 8
+6.875+5 7
,2 7
=(
+6.875)+(1 8
+2 7
),5 7
=(0.125+6.875)+1,
=7+1,
=8;
(2)
÷7 9
+11 5
×2 9
,5 11
=
×7 9
+5 11
×2 9
,5 11
=(
+7 9
)×2 9
,5 11
=1×
,5 11
=
;5 11
(3)
÷(1 3
-2 3
)×2 5
,3 5
=
÷1 3
×4 15
,3 5
=
×1 3
×15 4
,3 5
=
;3 4
(4)[
-(1 2
-3 4
)]÷3 5
,7 10
=[
-1 2
]÷3 20
,7 10
=
×7 20
,10 7
=
;1 2
(5)
X-1=0.2,1 8
X-1+1=0.2+1,1 8
X=1.2,1 8
X×8=1.2×8,1 8
X=9.6;
(6)X:
=21:5 14
,5 8
X=5 8
×21,5 14
X=5 8
,15 2
X×5 8
=8 5
×15 2
,8 5
X=12.