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计算.(能简算的要简算)64×6465256×254255-254×1255112+56-712+920-113012+16+112+120+130+142.

题目详情
计算.(能简算的要简算)
64×
64
65

256×
254
255
-254×
1
255

1
1
2
+
5
6
-
7
12
+
9
20
-
11
30

1
2
+
1
6
+
1
12
+
1
20
+
1
30
+
1
42
▼优质解答
答案和解析
(1)64×
64
65

=(65-1)×
64
65

=65×
64
65
-1×
64
65

=64-
64
65

=63
1
65


(2)256×
254
255
-254×
1
255

=256×
254
255
-
254
255
×1
=(256-1)×
254
255

=255×
254
255

=254

(3)1
1
2
+
5
6
-
7
12
+
9
20
-
11
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
4
-
1
4
+
1
5
-
1
6

=2-
1
6

=1
5
6


(4)
1
2
+
1
6
+
1
12
+
1
20
+
1
30
+
1
42

=(1-
1
2
)+(
1
2
1
3
)+(
1
3
-
1
4
)+(
1
4
-
1
5
)+(
1
5
-
1
6
)+(
1
6
-
1
7

=1-
1
2
+
1
2
1
3
+
1
3
-
1
4
+
1
4
-
1
5
+
1
5
-
1
6
+
1
6
-
1
7

=1-
1
7

=
6
7