What does it mean when a number is next to a variable?

It means the variable could be any number times the number in front of it. So 2x would be 2 times (x) or 10p would be 10 times (p), and usally you have to solve for the variable. An example would 5n + 6 = 21, so n would equal 3 because 5 times 3 eqauls 15 and 15 plus 6 equals 21.