解二元一次方程组有两种基本方法:代入法和加减法·它们都是通过将方程组变形,消去一个未知数,转化为一元一次方程,先求得这个未知数的值,再进而 There are two basic methods for solving binary equations: substitution method and addition and subtraction. They are all by deforming the equations, eliminating an unknown, and converting it into a one-dimensional equation. The value of this unknown is first obtained.