Problems on Numbers - General Questions

The sum of two numbers is 51 and their difference is 15. What is the larger number?

A number exceeds its one-fifth by 84. What is the number?

The sum of two numbers is 22 and their product is 105. What is the sum of their squares?

The sum of two numbers is 33 and their product is 270. What is the sum of their squares?

The sum of two numbers is 17 and their product is 70. What is the sum of their squares?