If x² + y² = 25 and xy = 12, what is the value of (x - y)²?

Question: If x² + y² = 25 and xy = 12, what is the value of (x - y)²?

Solution:
given,
x² + y² = 25
xy = 12

(x - y)² = x² + y² - 2xy
= 25 - (2 × 12)
= 1