Find the Remainder when $100!$ is divided by $97^2$? Find the Remainder when $100!$ is divided by $97^2$?
MyApproach
I applied Wilson Theorem here 
$100$.$99$.$98$.$97$.$96!\text{ mod }97^2=100$.$99$.$98$.$96!\text{ mod }97=-970200$
I am getting wrong Ans
Can Anyone guide me how to approach the problem?

First, compute $$a=100\cdot 99\cdot 98\pmod{97},$$ then
deduce that
$$-a=100\cdot 99\cdot 98\cdot 96!\pmod{97}$$
and that
$$-\color{red}{97}a=100!\pmod{97^{\color{red}2}}.$$
