Question : Regular Expression to match 7697998997 or 8724550

I am new to regular expression

Can some one help how to write regular expression for following

Number that is 10 digits long and start with 769 and followed by 7 numbers
eg:
7697998997

Other one
Number that is 7 digits long only.
please help

Answer : Regular Expression to match 7697998997 or 8724550

(769)?\d{7}