题目内容
已知:a2-b2=(a-b)(a+b);a3-b3=(a-b)(a2+ab+b2);a4-b4=(a-b)(a3+a2b+ab2+b3);按此规律,则:
(1)a5-b5=(a-b)(______);
(2)若a-
=2,你能根据上述规律求出代数式a3-
的值吗?
(1)a5-b5=(a-b)(______);
(2)若a-
| 1 |
| a |
| 1 |
| a3 |
(1)a4+a3b+a2b2+ab3+b4;
(2)a3-
=(a-
)(a2+1+
),
=(a-
)(a2-2+
+3),
=(a-
)[(a-
)2+3],
=2×(4+3),
=2×7,
=14.
(2)a3-
| 1 |
| a3 |
| 1 |
| a |
| 1 |
| a2 |
=(a-
| 1 |
| a |
| 1 |
| a2 |
=(a-
| 1 |
| a |
| 1 |
| a |
=2×(4+3),
=2×7,
=14.
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