aninditasivaram2406, 'Like' is generally used to compare between nouns whereas 'as' is used to compare between two clauses! Now if u refer the examples below -
Like X, Y is also a good singer. - Its fine because it compares between X and Y.
But,
I became poor in study as my brother was. It compares between two clauses.
Are you getting me, aninditasivaram2406?

Here is a tip, if u are confused between LIKE, AS, Such as.

Like is correct when you compare 2 nouns. It aso means "Similar to".
As is used when you compare 2 actions.
Such as is used when you want to be specific and want to give examples.


for example:
Can you buy me some fruits like oranges (this conveys that I need "juicy" fruits, which can or can not be oranges. Lemon will also do.)

Can you buy me fruits such as oranges (this means I need oranges in specific).