Question

走过路过,千万别错过.关于因式分解的..

Answer 1

1.

(x-y)的平方-16(x+y)的平方

=(x-y)^2-[4(x+y)]^2

=(x-y+4x+4y)(x-y-4x-4y)

=(5x+3y)(-3x-5y)

=-(5x+3y)(3x+5y)

2.

a+1/a=2/5

(a+1/a)^2=a^2+1/a^2+2=4/25

a^2+1/a^2-2=-96/25

(a-1/a)^2=-96/25

错误