问题
解答题
3.7×8.8+2.2×3.7-3.7
|
答案
(1)3.7×8.8+2.2×3.7-3.7,
=3.7×(8.8+2.2-1),
=3.7×10,
=37;
(2)
×{8 9
-(3 4
-0.25)},7 16
=
×(8 9
+3 4
-1 4
),7 16
=
×(1-8 9
),7 16
=
×8 9
,9 16
=
;1 2
(3)
+1 2
+1 6
+1 12
+1 20
,1 30
=(1-
)+(1 2
-1 2
)+(1 3
-1 3
)+(1 4
-1 4
)+(1 5
-1 5
),1 6
=1-
+1 2
-1 2
+1 3
+…+1 3
-1 5
,1 6
=1-
,1 6
=
.5 6