*) x² + 8x + 16 = x² + 2.x.4 + 4² = (x + 2)²
*) 4x² - 9 = (2x)² - 3² = (2x - 3)(2x + 3)
*) 125 - x³ = 5³ - x³ = (5 - x)(25 + 5x + x²)
*) 36 - 12x + x² = 6² - 2.6.x + x² = (6 - x)²
*) x³ + 12x² + 48x + 64
= x³ + 3.x².4 + 3.x.4² + 4³
= (x + 4)³
*) 8 - 12x + 6x² - x³
= 2³ - 3.2².x + 3.2.x² - x³
= (2 - x)³
*) 8x³ + 64 = (2x)³ + 4³
= (2x + 4)(4x² - 8x + 16)
= 2.4.(x + 2)(x² - 2x + 4)
= 8(x + 2)(x² - 2x + 4)
*) (5x - 1)³ = (5x)³ - 3.(5x)².1 + 3.5x.1² - 1³
= 125x³ - 75x² + 15x - 1
*) x² - 2 = x² - (căn 2)²
= (x - căn 2)(x + căn 2)
*) x³ + 1/27 = x³ + (1/3)³
= (x + 1/3)(x² - x/3 + 1/9)
x2 + 8x + 16
= x2 2.x.4 + 42 = (x + 4)2
---------------------------------
4x2 - 9
= 4x2 - 32 = (4x - 3) (4x + 3)
-------------------------------------
125 - x3
= 53 - x3 = (5 - x) (52 + x2)
-------------------------------------
8 - 12x + 6x2 - x3
= (2 - x)3
X^2+8x+16
=x^2+2x4+4^2
=(x+4)^2
------------------------------------------
4^2-9
=4^2-3^2
=(4-3) (4+3)
--------------------------------------
125-x^3
=5^3-x^3
=(5-x) (5^2+5x+x^2)
----------------------------
36-12×+×^2
=6^2-2×6+×^2
(6-x)^2
