Get personalized answers to your specific questions with IDNLearn.com. Discover comprehensive answers to your questions from our community of experienced professionals.
Recall that (a + b)² = a² + 2ab + b².
Let a = x² and b = y². Then
(x² + y²)² = (x²)² + 2x²y² + (y²)²
⇒ x⁴ + y⁴ = (x² + y²)² - 2 (xy)²
Given that x² + y² = 13 and xy = 6, we have
x⁴ + y⁴ = 13² - 2×6² = 97