X - y = 10 Xy = 10 Tentukan x⁴ + y⁴

x - y = 10
xy = 10

(x - y)² = x² + y² - 2xy
(10)² = x² + y² - 2(10)
100 = x² + y² - 20
x² + y² = 100 + 20
x² + y² = 120

(x² + y²)² = x⁴ + y⁴ + 2x²y²
(120)² = x⁴ + y⁴ + 2(xy)²
14400 = x⁴ + y⁴ + 2(10)²
14400 = x⁴ + y⁴ + 200
x⁴ + y⁴ = 14400 - 200
x⁴ + y⁴ = 14200