我们知道,解一次方程组可以通过逐步“消元”,变“多元”为“一元”,从而达到求解的目的.因此,对“元”的认识有助于“消元”;巧妙地掌握“消元”技巧有助于变“多元”为“一元”.现举例说明. 一、代入法消元一般是从方程组中选一个系数比较简单的方程,将这个方程中的一个未知数,例如y,用含x的代数式表示出来,即写成y=ax+b的形式代入另 We know that solving a system of equations can be solved gradually by “eliminating yuan” and changing “multivariate” to “yiyuan” so as to achieve the goal of solving. Therefore, the understanding of “yuan” helps to “eliminate yuan” and master it subtly. Elimination “skills help change the ”multivariate“ to ”universe". Here is an example. First, the substitution elimination method is generally to select a simpler equation from the equations, and to use an unknown number in this equation, such as y, Express it with an algebraic expression containing x, that is, write the form y=ax+b to substitute another