What are the missing variables

Pls! does anybody know a shortcut for answering these types of questions in the future?

The difference between the number of electoral votes for florida and north carolina is 12 votes. write and solve a subtraction equation to find a number of electoral votes for florida.

Mr. roseanne will buy 12 1/2 pounds beef for for a cookout. the price for the first 3 pounds of beef is $4.99 per pound. after that, the price is $4.49 per pound. how much will mr.roshan pay for the beef