a = 5, b = 4, c = 8 అయితే, (a3 + b3 + c3 – 3abc) / (ab + bc + ca – a2 – b2 – c2). A. 15 B. 17 C. -17 D. -15

a³ + b³ + c³ − 3abc = (a + b + c)(a² + b² + c² − ab − bc − ca), and the denominator is −(a² + b² + c² − ab − bc − ca). So the expression = −(a + b + c) = −(5 + 4 + 8) = −17.