14x²-67xy+18y²= (2x-9y)(7x-2y)与14x²-67xy+18y²= (9y-2x)(2y-7x)是不是都对?为什

分类: 作业答案 • 2022-03-17 15:33:32

问题描述：

14x²-67xy+18y²= (2x-9y)(7x-2y)与14x²-67xy+18y²= (9y-2x)(2y-7x)是不是都对?为什
详尽点啊

答

(2x-9y)(7x-2y)
=14x^2-4xy-63xy+18y^2
=14x^2-67xy+18y^2
正确
(9y-2x)(2y-7x)
=[-(2x-9y)][-(7x-2y)]
=(2x-9y)(7x-2y)
和前一个一样
所以也正确