The sum of two numbers is 8. The sum of the squares of the same two numbers is 40. What are the numbers? Click on image to enlarge if needed
3 and 5
4 and 4
2 and 6
1 and 7

Please help I need help

The party planning committee has to determine the number of tables needed for an upcoming event. if a square table can fit 8 people and a round table can fit 6 people, the equation 150 = 8x + 6y represents the number of each type of table needed for 150 people.