Question

If x – y = 2 and x² + y² = 34, find the value of xy.

Answer 1

Given:

• x – y = 2
• x² + y² = 34

Step-wise calculation:

1. Use the identity:

(x – y)² = x² + y² – 2xy

2. Substitute the given values:

2² = 34 – 2xy

4 = 34 – 2xy

3. Rearrange to solve for xy: 

2xy = 34 – 4

2xy = 30

xy = `30/2`

xy = 15