If the number x is 3 less than the number y and the sum of the squares of x and y is 29, find the product of x and y.

If the sum and the product of two numbers are 8 and 15 respectively, find the sum of their cubes.

If x² + y² = 9 and xy = 8, then x + y is equal to

1. 25

2. 5

3. -5

4. ±5

(102)² - (98)² is equal to

1. 200

2. 400

3. 600

4. 800