Verified Answer :

\(64 x^{3} -125\)

= \((4x)^{3} - 5^{3}\) ------> because, \((4x)^{3}\) is same as 64x³ and 
                                                \(5^{3}\) is same as 125

Using the formula: \(a^{3}- b^{3} =(a-b)(a ^{2} +ab+b ^{2} )\), we get, 

= \((4x -5)((4x)^{2} +4x*5+ 5^{2} )\)

= \((4x -5)(16 x^{2} +20x+25)\)   ------>that's your answer!!