Question

hey guys . tell me the formulae of a3 - b3 - c3 -3abc and also verify​

Answer 1

Answer:

(a3 – b3) = (a – b)(a2 + b2 + ab)

Let us prove this by considering a = 4 and b= 2 then

(43 – 23) = (4 – 2)(42 + 22 + 4 × 2)

LHS = (2)(28)

LHS = 56

RHS = (a – b)(a2 + b2 + ab)

RHS = (4 – 2)(42 + 22 + 4 × 2)

RHS = 56

∴ LHS = RHS

(a3 – b3) = (a – b)(a2 + b2 + ab)

Hence the proof.

Answer 2

(a³ + b³+ c³ - 3abc) = (a + b + c)*(a² + b² + c²- ab - bc - ac) 13.