what is the mathematical formulas of Math.Random

I saw this quote a c# guide site:

C#.NET comes with a built-in random number generator that is accessed through the Random class. The thing about the C# Random class however is that it generates pseudo-random numbers. That means that random numbers come from mathematical formulas that generate sequences of numbers that appear to be random...

someone knows what is the mathematical formulas of the random function in the math class and how can I change it in my code?