(1)2x²-7x+3= (2)6x²-7x-5 (3)5x²+6xy-8y²
问题描述:
(1)2x²-7x+3= (2)6x²-7x-5 (3)5x²+6xy-8y²
答
解
2x²-7x+3
2 -1
1 -3
十字相乘法
=(2x-1)(x-3)
6x²-7x-5
2 1
3 -5
=(2x+1)(3x-5)
5x²+6xy-8y²
5 -4
1 2
=(5x-4)(x+2)