If 9x2 + 6xy + 4y2 is a factor of 27x3 - 8y3, find the other factor.
2y + 3x
2y - 3x
3x + 2y
3x - 2y
Correct answer is D
27x3 - 8y3 = (3x - 2y)3
But 9x2 + 6xy + 4y2 = (3x +2y)2
So, 27x3 - 8y3 = (3x - 2y)(3x - 2y)2
Hence the other factor is 3x - 2y