Examveda
Examveda

If a + b + c = 8 and ab + bc + ca = 12, then a3 + b3 + c3 - 3abc is equal to:

A. 192

B. 224

C. 144

D. 400

Answer: Option B

Solution(By Examveda Team)

a + b + c = 8 and ab + bc + ca = 12
a3 + b3 + c3 - 3abc = ?
Let c = 0
a + b = 8, ab = 12
a3 + b3 = (a + b)(a2 + b2 - ab)
a3 + b3 = (a + b)[(a + b)2 - 3ab]
a3 + b3 = 8[82 - 3 × 12]
a3 + b3 = 224

This Question Belongs to Arithmetic Ability >> Algebra

Join The Discussion

Related Questions on Algebra