Question

因式分解的简单应用

x²+6x-16

4x的3次方-20x²+24x

m²-a²+4ab-4b²

5m-m²-5n+2mn-m²

9x²-y²-4y-4

m²+2n-mn-2m
急，明天就要交了

Answer 1

x²+6x-16
=(x-2)(x+8)

4x的3次方-20x²+24x
=4x(x^2-5x+6)
=4x(x-2)(x-3)

m²-a²+4ab-4b²
=m^2-(a-2b)^2
=(m+a-2b)(m-a+2b)

5m-m²-5n+2mn-m²
请确认是否是5m-m²-5n+2mn-n²
=5（m+n）-(m+n)^2
=（m+n）(5-m-n)

9x²-y²-4y-4
=9x^2-(y+2)^2
=(3x+y+2)(3x-y-2)

m²+2n-mn-2m
=(m^2-2m)-(mn-2n)
= m(m-2)- n(m-2)
= (m-n)(m-2)

Answer 2

前一年学的，不知不觉忘了