a) (a-3)(a+3)
b)(2x-5)(2x+5)
c)(x3-y3)(x3+y3)
a) x2 - 9 = x2- 32
= (x-3)(x+3)
b) 4x2 - 25 = (2x)2 - 52
= (2x-5)(2x+5)
c) x6- y6 = (x3)2 - (y3)2
= (x3-y3)(x3+y3)
= (x-y)(x2-xy+y2)(x2+xy+y2)(x+y)
Phân tích thành nhân tử:
a) x2 - 9 = x2 - 32 = (x + 3)(x - 3)
b) 4x2 - 25 = (2x)2 - 52 = (2x + 5)(2x - 5)
c) x6 - y6 = (x3)2 - (y3)2 = (x3 + y3)(x3 - y3) = (x - y)(x2 + xy + y2)(x + y)(x2 - xy + y2).