题目内容
(
+
+
+
)×(
+
+
+
)-(
+
+
+
+
)× (
+
+
)．
| 1 |
| 11 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
| 1 |
| 51 |
| 1 |
| 11 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
| 1 |
| 51 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
分析：因为数值较大，令
+
+
+
=a，
+
+
=b，然后用字母进行表示，然后再进行计算即可．
| 1 |
| 11 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
解答：解：令
+
+
+
=a，
+
+
=b，
则原式=a×（b+
）-（a+
）×b
=ab+
a-ab-
b
=
×（a-b）
=
×[（
+
+
+
）-（
+
+
）]
=
×
=
；
| 1 |
| 11 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
则原式=a×（b+
| 1 |
| 51 |
| 1 |
| 51 |
=ab+
| 1 |
| 51 |
| 1 |
| 51 |
=
| 1 |
| 51 |
=
| 1 |
| 51 |
| 1 |
| 11 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
| 1 |
| 21 |
| 1 |
| 31 |
| 1 |
| 41 |
=
| 1 |
| 51 |
| 1 |
| 11 |
=
| 1 |
| 561 |
点评：本题运用字母表示出较长的算式，便于计算书写．
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