问题
解答题
计算: (1)(π-
(2)(x+y)2-(x-y)2. |
答案
(1)原式=1+9+32
=10+3
;2
(2)原式=x2+2xy+y2-(x2-2xy+y2)
=x2+2xy+y2-x2+2xy-y2
=4xy.
计算: (1)(π-
(2)(x+y)2-(x-y)2. |
(1)原式=1+9+32
=10+3
;2
(2)原式=x2+2xy+y2-(x2-2xy+y2)
=x2+2xy+y2-x2+2xy-y2
=4xy.