Credit Cards Bad Scoring Is Having A Lot Of Credit Cards Good Or Bad For Your Credit Score?

Is having a lot of credit cards good or bad for your credit score? - credit cards bad scoring

I've heard so ... My teacher said to have many credit cards to my account. But I also read a portion of your credit score is calculated by the formula

How should / total loans, which would be better in this case more tickets. I have 7 cards and I only 2 of them. Should I my other cards?