That's easy. I did that in the last unit of my math. First, you have to do the Order of Operations, or PEMDAS (Parantheses, Exponents, Multiplication and Division, and Addition and Subtraction). You've been getting the answer wrong because you didn't follow the Order of Operations correctly. First, you have to do whatever is in the parentheses, if there are any, which in your problem is x+2. If your teacher says that x=3, then that's like the answer key, so you change x to 3, not 1. So, 3+2=5. Then, you have to do the next step in the Order of Operations, Multiplication or Division. Since you have Multiplication, you have to times 4 x 5, which equals 20. It doesn't equal 14, and when you got that answer, you did the Order of Operations wrong. If you change your answer to 20, you'll get it right. You also have to do PEMDAS on every single Order of Operations equation like that, or you'll get it wrong.