q) (2x - 3)(2x + 3) = (2x)2 - 32
= 4x2 - 9
r) (2x - 3y)(2x + 3y) = (2x)2 - (3y)2
= 4x2 - 9y2
s) (3 - 2x)3 = 33 - 3.32.2x + 3.3.(2x)2 - (2x)3
= 27 - 54x + 36x2 - 8x3
t) (2x + 1)3 = (2x)3 + 3.(2x)2.1 + 3.2x.12 + 13
= 8x3 + 12x2 + 6x + 1
u) x3 + 1 = x3 - 13
= (x - 1)(x2 + x + 1)
v) x3 - 8 = x3 - 23
= (x - 2)(x2 + 2x + 4)
w) 27 - x3 = 33 - x3
= (3 - x)(9 + 3x + x2)
x) 27x3 + 8y3 = (3x)3 + (2y)3
= (3x + 2y)(9x2 - 6xy + 4y2)
Chúc bạn học tốt
j) x2 - 9y2 = x2 - (3y)2
= (x - 3y)(x + 3y)
k) 4x2 - 25y2 = (2x)2 - (5y)2
= (2x - 5y)(2x + 5y)
Chúc bạn học tốt
j) \(x^2-9y^2=\left(x-3y\right)\left(x+3y\right)\)
