数学高手来..加急

来源:百度知道 编辑:UC知道 时间:2024/06/06 18:21:02
计算下列各题
(2x-4y)(5x-3y)
3(x-1)(x+4)-2(x+5)(x-2)
急..题目没有错误 谢谢帮忙
要写过程

解:
=10X^2-6XY-20XY+12Y^2
=10X^2-26XY+12Y^2

解:
=(3X-3)*(X+4)-(2X+10)*(X-2)
=(3X^2+12X-3X-12)-(2X^2-4X+10X-20)
=(3X^2+9X-12)-(2X^2+6X-20)
=3X^2+9X-12-2X^2-6X+20
=X^2+3X+8

一定要说好! 我的有过程哦 呵呵 ~~~~~~~~~~~~~````

=10x^2-26xy+12y^2

=3(x^2+3X-4)-2(x^2+3x-10)
=3x^2+9x-12-2x^2-6x+20
=x^2+3x+8