How many phone numbers are possible in the 512 area code if: for the form ABC-, a and b are restricted to 3-9 but c and x can be any digit 0-9

38 dollars is your answer.

Answerthe simplified expression isexplanationthe given expression is,let us deal with the bracket first.the two negatives in the parenthesis will become positive.the expression now becomes,we now expand the parenthesis to get,we group like terms to obtain,this simplifies to,