Question

12.

If a,b,c are distinct positive real numbers and 4a^2 + 9b^2 + c^2 = 4, then 6ab + 3bc + 2ca is -
(A) equal to 4
(B) less than 4
(C) greater than 4
(D) any positive real number​

Answer 1

( c ). Greater then 4

Answer 2

first try it yourself then ask me only then after I tell you .