Exercise P5.1 of Page 221:

Write a program that prints all real solutions to the quadratic equation ax² + bx + c = 0.
Read in a, b, c and use the quadratic formula.  If the discriminant b²-4ac is negative, display a message stating that there are no real solutions.

Implement a class QuadraticEquation whose constructor receives the coefficients a, b, c of the quadratic equation.  Supply methods getSolution1 and getSolution2 that get the solutions, using the quadratic formula, or 0 if no solution exists.  The getSolution1 method should return the smaller of the two solutions.  Supply a method boolean hasSolutions() that return false if the discriminant is negative.