问题
解答题
计算: (1)(
(2)(x+2y)(x-2y)-(x-2y)2. |
答案
(1)(
)-2-(3-π)0+231 4
=16-1+8
=23;
(2)(x+2y)(x-2y)-(x-2y)2
=x2-4y2-x2+4xy-4y2
=4xy-8y2.
计算: (1)(
(2)(x+2y)(x-2y)-(x-2y)2. |
(1)(
)-2-(3-π)0+231 4
=16-1+8
=23;
(2)(x+2y)(x-2y)-(x-2y)2
=x2-4y2-x2+4xy-4y2
=4xy-8y2.