Hello, do you know if is possible to use adwords for a website in wich are some adsense ads? thank you in advance for your replies
Instead of going by what you've "heard" you might consider reading Google's Adwords and Adsense policies. There's absolutely no prohibition on promoting sites running Adsense with Adwords, but what is prohibited is direct arbitrage, specifically buying cheap and unrelated traffic from anywhere, including Adwords, and driving it to an MFA or similar where the primary goal and monetization is Adsense.