Examveda
Examveda

If (a + 4)3 = a3 + 12a2 + ka + 64, then what is the value of k?

A. 45

B. 46

C. 47

D. 48

Answer: Option D

Solution(By Examveda Team)

(a + b)3 = a3 + 3a2b + 3ab2 + b3 . . . . . . . . (i)
(a + 4)3 = a3 + 12a2 + ka + 64
= (a)3 + 3.a2.4 + k.a + (4)3 . . . . . . . . (ii)
Comparing equation (i) and (ii) we get,
b = 4 and k = 3k2
∴ k = 3 × 42 = 48

This Question Belongs to Arithmetic Ability >> Algebra

Join The Discussion

Related Questions on Algebra