Cool Birthday Puzzle

Test your arithmetic skills with this series of calculations:

Write the number of the month in which you were born.
Multiply by 4.
Add 13.
Multiply by 25.
Subtract 200.
Add the day of the month you were born.
Multiply by 2.
Subtract 40.
Multiply by 50.
Add the last two digits of the year you were born.
Subtract 10,500.

If you made no mistakes, the answer should give your birthday in mmddyy format. Now test your algebra skills:

Can you explain why this works?

It worked for me..when I figure out how it works, I'll post a comment.
have a go at it!

you can probably find the answer by following this source link