Tayler9681 Tayler9681 09-02-2024 Mathematics contestada Sarah is demonstrating the idea that polynomials are closed under addition. Her work and explanation are shown.Add 3x⁴ + 61 toA: 2z³ - (2x)² + 4x⁻¹B: (2x)² + 4.4x - 9C: (-8z)⁻² - (3x)³ + 7