代数方程是未知数和常数进行有限次代数运算所组成的方程。代数方程包括有理方程和无理方程。有理方程又包括整式方程与分式方程。整式方程，就是所谓的“多项式方程”。

一元一次方程都可化为其标准形式ax+b=0（a≠0）。解一元一次方程通常使用以下五步进行求解：“去分母”、“去括号”、“移项”、“合并同类项”、“系数化为1”。

解一元n次方程（n≥2，n为正整数）往往可以通过因式分解，化为n个一次因式的乘积，进而解出方程所有的根。

另外，二次、三次、四次方程还可以利用求根公式求出其所有的根。然而，伽罗瓦理论指出，对于五次及其以上的一元整式方程，并不存在通用的求根公式。

In mathematics, an algebraic equation or polynomial equation is an equation of the form

where P and Q are polynomials with coefficients in some field, often the field of the rational numbers. For most authors, an algebraic equation is univariate, which means that it involves only one variable. On the other hand, a polynomial equation may involve several variables, in which case it is called multivariate and the term polynomial equation is usually preferred to algebraic equation.