( 8.73 x 8.73 x 8.73 + 4.27 x 4.27 x 4.27 ) / ( 8.73 x 8.73 - 8.73 x 4.27 + 4.27 x 4.27 ) is equal to?

Let a = 8.73 and b = 4.27
Then, given expression =( a³ + b³ ) / ( a² - ab + b² )
As we Know the Algebra formula,
a³ + b³ = (a + b) (a² - ab + b²)
Apply the above algebra formula in given above expression,
= (a + b) (a² - ab + b²) / ( a² - ab + b² )
= (a + b)
= 8.73 + 4.27 = 13