为以下两个数学方程，提供解决方案。（a）5x + 3 = 28，(b) 3x²+ 5x - 2 = 0
(a)5x + 3 = 28，(b)3x²+ 5x - 2 = 0
(a) 解方程：5x + 3 = 28
     5x = 28-3 
     5x = 25 
     x = 5 

(b) 解方程：3x²+ 5x - 2 = 0
     可以使用求根公式（Quadratic Formula）：x = (-b ± √(b²-4ac)) / (2a)
     对应该方程中，a = 3，b = 5，c = -2
     x = (-5 ± √(5²- 4(3)(-2))) / (2*3)
     x = (-5 ± √49) / 6
     x = (-5 ± 7) / 6
     x1 = 2/3，x2 = -1