Question

Evaluate using suitable identity (42)³-(18)³-(24)³

Answer 1

Answer:

31104

Step-by-step explanation:

let a=42; b= -18 ; c= -24

now we ought to find out 42³ + (-18)³ + (-24)³

ie., a³+b³+c³

we here have  a+b+c = 42+(-18)+(-24) = 0

∴ we can use the formula a³+b³+c³ = 3abc

hence ,

42³ + (-18)³ + (-24)³ = 3 (42)(-18)(-24)

                               = 31104