express the given higher-order differential equation as a matrix system in normal form. mass-spring oscillator equation 7. The damped my" +by' + ky = 0 8. Legendre's equation (1-1²)y"-2ty' + 2y = 0 9. The Airy equation y" - ty = 0 10. Bessel's equation y"+y' + + ₁ x ² + (₁ - 1²/²]) y = 0 (1 In Problems 11-13, express the given system of higher- order differential equations as a matrix system in normal form. 11. x" + 3x + 2y = 0, y"-2x = 0