问题
解答题
(1)762-357+438-243 (2)(
(3)(200.6×365+2006×63.5)×40% (4)4
(5)(0.5+
(6)
|
答案
(1)762-357+438-243,
=(762+438)-(357+243),
=1200-600,
=600;
(2)(
+3 4
-1 6
)÷5 12
,1 36
=(
+3 4
-1 6
)×36,5 12
=
×36+3 4
×36-1 6
×36,5 12
=27+6-15,
=33-15,
=18;
(3)(200.6×365+2006×63.5)×40%,
=(200.6×365+200.6×635)×40%,
=(365+635)×200.6×40%,
=1000×200.6×0.4,
=200600×0.4,
=80240;
(4)4
×5+321 5
÷4+0.25×124,4 7
=(4+
)×5+(32+1 5
)×4 7
+0.25×4×31,1 4
=4×5+
×5+32×1 5
+1 4
×4 7
+1×31,1 4
=20+1+8+
+31,1 7
=(20+1+8+31)+
,1 7
=60+
,1 7
=60
;1 7
(5)(0.5+
+31 4
÷1.25)÷(51 8
-1.25×11 4
),3 5
=(0.5+
+2.5)÷(51 4
-2),1 4
=(0.5+2.5+
)÷(51 4
-2),1 4
=(3+
)÷31 4
,1 4
=3
÷31 4
,1 4
=1;
(6)
+2 3
+2 15
+…+2 35
,2 399
=(1-
)+(1 3
-1 3
)+(1 5
-1 5
)+…+(1 7
-1 19
),1 21
=1-
+1 3
-1 3
+1 5
-1 5
+…-1 7
+1 19
-1 19
,1 21
=1-
,1 21
=
.20 21