第一章算术 Arithmetic 分数、小数和比例 fractions,decimals and percent 分子 numerator part 分母denominator whole(the base of the percent) Triangle inequality:|a+b|<=|a|+|b| 错题: n=a^x×b^y×c^z a b c为质数 npositive factors有(x+1)(y+1)(z+1)个 87是合数!! 二三章 Algebra 代数 遇到real integer一定一定要小心!!! 0算术平方根仍为零。 化简根式simplifying radicals。 Coefficient 系数 constant 常数 estate 遗产 Functions 函数 自变量independent variable The terms 5z2 and -z2 are called like terms 20y2 + 6y -17 = 0 A quadratic equation in one variable,y (x,y):ordered pair simultaneous equations Simultaneous equations 联立 quadratic equation 二次方程 The domain of a function is the set of all permissible inputs. dimes 10分硬币 quarters 25分硬币 12周