If (a-b) = 5 and ab= 150, then what is the value of (a3-b3)?

If (a-b) = 5 and ab= 150

Then, 

( a - b )² = a² + b² - 2ab

(5)² = a² + b² - 2 × 150

 a² + b²  = 325

a³ - b³ = ( a - b ) ( a² + b² + ab )

a³ - b³ = ( 5 ) ( 325 + 150 )

a³ - b³ = 2375