Đáp án+Giải thích các bước giải:
`a) x³ + 6x² + 12x + 8 = x³ + 3.x².2 + 3.x.2² + 2³ = (x+2)³`
`b) x³ - 3x² + 3x - 1 = x³ - 3.x².1 + 3.x.1² - 1³ = (x-1)³`
`c) 1-9x+27x²-27x³ = -(27x³ - 27x² + 9x - 1) = -[(3x)³ - 3.(3x)².1 + 3.3x.1² - 1³] = -(3x-1)³`
`d) x³ + (3/2)x² + (3/4)x + 1/8 = x³ + 3.x².(1/2) + 3.x.(1/2)² + (1/2)³ = (x+1/2)³`
`e) 27x³ -54x²y + 36xy² - 8y³ = (3x)³ - 3.(3x)².2y + 3.3x.(2y)² - (2y)³ = (3x-2y)³`
`f) x²-2xy+y² -4m² = (x²-2xy+y²) -4m² = (x-y)² - (2m)² = (x-y-2m)(x-y+2m)`