**HINT:-**
An approach which does not involve modular arithmetic.
R.T.P.
$2^{2x} \equiv 1 \mod 3$
or,$2^{2x}-1$ is divisible by $3$.
Now,$2^{2x}=4^x$
So,prove by induction now that $4^x-1$ is divisible by $3.$.'
**HINT:-**
An approach which does not involve modular arithmetic.
R.T.P.
$2^{2x} \equiv 1 \mod 3$
or,$2^{2x}-1$ is divisible by $3$.
Now,$2^{2x}=4^x$
So,prove by induction now that $4^x-1$ is divisible by $3.$.'