因式分解:2a²-6a-20

问题描述:

因式分解:2a²-6a-20

2 a ² - 6 a - 20
= 2(a ² - 3 a - 10)
= 2(a - 5)(a + 2)
十字相乘法:x ² + (p + q)x + p q = (x + p)(x + q)