Question

Desenvolvendo os cubos:
(x-4)³

(2x-3y)³

(ab+3)³

Answer 1

(x - 4)³

(x - 4)(x- 4)(x - 4)
(x² - 2.4.x + 16)(x - 4)
(x² - 8x + 16).(x - 4)
x³ - 4x² -8x² + 32x  + 16x - 64
=> x³ - 12x² + 48x - 64 

===

(2x - 3y)³

(2x - 3y).(2x - 3y).(2x - 3y)

4x² - 6xy - 6xy + 9y² (2x - 3y)
4x² - 12xy - 9y² (2x - 3y)
=> 8x³ - 36x²y + 54xy² - 27y³

===

(ab + 3)³
(ab + 3).(ab + 3).(ab + 3)

(a²b² + 3ab + 3ab +9) (ab + 3)
=> a³b³ + 9a²b² + 27ab + 27