多项式的加减乘运算，没有除运算，算法很清楚，都可以看懂-polynomial modified by the operator, the operator is no exception, the algorithm is very clear, can understand

分数类，就是包含分数和整数，分数和分数之间的加，减，乘，除-Scores of classes, that contains the scores and integers, between the scores and scores of add, subtract, multiply, divide