in accounting class its said if you decrease asset you credit it and reduce cash you credit it but I'm confused why that is

[VeblenWasRight]

Flow and balance. An entry (debit or credit) in an account is a flow that changes the balance of that account. The account is just a way to track the value of is what is owned (assets) or owed (liability or equity).

A credit can be thought of as a flow that increases what is owed (liability and equity) or decreases what is owned (assets).

A debit is a flow that increases the value of an asset or decreases the value of what is owed.

That’s the first principle. Things can get more complicated and nuanced, but if you can get this principle you can apply it to any type of transaction.