Write an algebraic expression that describes the following word phrase, using the letter `a` for the unknown number.
nine times a number minus two = a 

Write an algebraic expression that describes the following word phrase, using the letter `a` for the unknown number.
nine times a number minus ten = a 

Write an algebraic expression that describes the following word phrase, using the letter `a` for the unknown number.
two times a number plus four = a +

Write an algebraic expression that describes the following word phrase, using the letter `a` for the unknown number.
ten times a number minus three = a 
