What are some facts about the ural mountains?

Some facts about the Ural Mountains are: 1. Were formed 300 million years ago 2. The Ural mountains, together with the Appalachians, are among the oldest mountains in the world. 3. The Urals have been a natural barrier for humans. During World War II Soviet forces planned to retreat east of the Urals in case Nazi’s invasion would have been eventually successful. 4. The Urals act as a natural barrier to winds from the Atlantic

Answer were lower;

5×^2+20-15 or -(5x^2-20+15)