X and y being "congruent" under modulo n is denoted by "x ≡ y mod n" and defined as "x and y having the same remainder when divided by n." Show the following congruences. Required:
Show that the smallest k for 1640 ≡ k mod 7 is k = 2.

How is a wan different than a lan? both connect computers, but only wan users don’t need the same operating system. both are peer-to-peer networks, but only a wan requires networking hardware. both network computers, but only a wan can cover larger geographical ranges. both connect computers to the internet, but only wan connects to the cloud.