“Three more” means +3. Imagine you have 2 apples, and I have 3 more than you. I have 5 apples then, right?
“Product” — the product of 2 and 1 is 2. The product of 3 and 5 is 15. So: the product is the result of multiplication. Thus, “the product of two and x” would mean we have to multiply 2 and x.
So lets combine these: “2*x+3” would be your answer, or if you want, shorten the “2*x” to just “2x”.