This is an example of an expression. Expressions can have numbers, variables and symbols (like add, subtract, multiply, divide, parentheses, etc). The difference between an expression and an equation is that an equation has an equal sign in it. If this were an equation, you would need to solve it and find the value of x. However, here, all you need to do is simplify the expression. This expression is not in its simplest form since you can combine the -2 and the +12.
One way to simplify the expression is to rewrite it and put the numbers next to each other. So you can write
+5x+12-2 This then becomes
You can't simplify the above expression any further since they are unlike terms. One term has a variable and the other is just a number by itself. If you had, let's say 5x+10-2x, the like terms would be the 5x and the -2x since they both have exactly the same variable. But since you have no other x term to combine with the +5x, once you get to +5x+10 which is the same as 5x+10, you are done.
Does this answer your question>