问题
解答题
计算;(1)(x-3y)(x-
(2)4x2-(-2x+3)(-2x-3). |
答案
(1)(x-3y)(x-
y),1 2
=x2-
xy-3xy+1 2
y2,3 2
=x2-
xy+7 2
y2;3 2
(2)4x2-(-2x+3)(-2x-3),
=4x2-(4x2-9),
=9.
计算;(1)(x-3y)(x-
(2)4x2-(-2x+3)(-2x-3). |
(1)(x-3y)(x-
y),1 2
=x2-
xy-3xy+1 2
y2,3 2
=x2-
xy+7 2
y2;3 2
(2)4x2-(-2x+3)(-2x-3),
=4x2-(4x2-9),
=9.