Question

Which of the following is a difference of cubes? x^6 + 27y^9 3x^9 - 64y^3 27x^{15} - 9y^3 125x^{21} - 64y^3

Answer 1

D) 125x²¹- 64y³

Explanation:

A) x⁶ + 27y⁹ = (x²)³ + (3y³)³ - sum of cubes

B) 3x⁹ - 64y³ - the first term is not a cube

C) 27x¹⁵ - 9y³ - the second term is not a cube

D) 125x²¹- 64y³ = (5x⁷)³ - (4y)³ - difference of cubes

Correct option is the last one

Answer 2

• D) 125x²¹- 64y³

Explanation:

• A) x⁶ + 27y⁹ = (x²)³ + (3y³)³ - sum of cubes
• B) 3x⁹ - 64y³ - the first term is not a cube
• C) 27x¹⁵ - 9y³ - the second term is not a cube
• D) 125x²¹- 64y³ = (5x⁷)³ - (4y)³ - difference of cubes

Correct option is the last one