古人打仗,兵马未动,粮草先行.我们学代数,也需要“粮草”,它就是各种各样的数. 回忆初一代数,就是从有理数学起的.有了有理数,才可以学习整式和分式的四则运算、因式分解、一次方程(组)以及一元一次不等式等内容.如果没有有理数 The ancients used to fight wars, horses and horses did not move, food and grass first. We need to learn algebra, also need to “grass grass”, it is a variety of numbers. Memories of the first generation number, is from rational mathematics. With rational numbers, we can learn the whole formula Fractional quadratic operations, factorization, first-order equations (groups), and unary inequalities. If there is no rational number