题目内容
计算:
(1)(2a-b)(b+2a)-(3a+b)2
(2)(
)-2-(
-1)0
(3)简便方法计算:(-0.25)2009×42010.
(1)(2a-b)(b+2a)-(3a+b)2
(2)(
| 1 |
| 2 |
| 3 |
(3)简便方法计算:(-0.25)2009×42010.
(1)原式=4a2-b2-(9a2+6ab+b2)
=4a2-b2-9a2-6ab-b2
=-5a2-2b2-6ab;
(2)原式=4-1=3;
(3)原式=(-0.25)2009×42009×4=(-0.25×4)2009×4=-1×4=-4.
故答案为-5a2-2b2-6ab、3、-4.
=4a2-b2-9a2-6ab-b2
=-5a2-2b2-6ab;
(2)原式=4-1=3;
(3)原式=(-0.25)2009×42009×4=(-0.25×4)2009×4=-1×4=-4.
故答案为-5a2-2b2-6ab、3、-4.
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