Đáp án:
(x² + 2)³ = x⁶ + 6x⁴ + 12x² + 8
(x - 1/2)³ = x³ - 3/2x² + 3/4x - 1/8
(1/2x - y²)³ = 1/8x³ - 3/4x²y² + 3/2xy⁴ - y⁶
Giải thích các bước giải:
(x² + 2)³
= (x²)³ + 3.(x²)².2 + 3.x².2² + 2³
= x⁶ + 6x⁴ + 12x² + 8
(x - 1/2)³
= x³ - 3.x².1/2 + 3.x.1/4 + (1/2)³
= x³ - 3/2x² + 3/4x - 1/8
(1/2x - y²)³
= (1/2x)³ - 3.(1/2x)².y² +
3.1/2x.(y²)² - (y²)³
= 1/8x³ - 3/4x²y² + 3/2xy⁴ - y⁶