Prove that for any integer x ,the integer x(x+1) is even by direct proof​

Larry sent an email to andy. andy didn't open larry's email but still understood what the message was. how did andy determine the message without opening the email?

Wich technology can a website use to allow you to listen to a concert live over the internet?

You have a small company and want to keep your costs low, but it is important your employees share data. which network would provide you with the most economical solution?