If $3x+5$ is the LHS of an equation and the value of x is 3, what is/are the possible RHS(s) of the equation?

The correct option is C $\frac{6}{x}+12$
In an equation the value of the LHS and the RHS should be equal.
The LHS of the equation is given as
$3x+5$ and the value of x is 3. So, value of the LHS is
$3\times 3+5=14$.

Among the four options the first and fourth expressions have value 14.
Because,
$2x+8=2\times 3+8=14$
and
$\frac{6}{x}+12=\frac{6}{3}+12=2+12=14$.

Hence, the $2x+8$ and $\frac{6}{x}+12$ are the possible RHS for the given equation.