同学们已学习过一元二次方程的两种解法:公式法和因式分解法,这里再介绍一元二次方程的另一种解法——均值换元法.先看下面的例子例1 解方程3x~2+5(2x+1)=0. 解去括号,得3x~2+10x+5=0. 二次项系数化为1,得x~2+10/3x+5/3=0. 由根与系数的关系,可设原方程的两根分别为-5/3+k、-5/3-k(k≥0), The students have studied two solutions of the quadratic equation of quadratic equation: formula method and factorization method. Here we introduce another method of one-dimensional quadratic equation—mean value conversion method. Let’s look at the following example. Example 1 Solution equation 3x~2+5(2x+1)=0. Uncomment the parentheses and get 3x~2+10x+5=0. The quadratic term coefficient is 1 and get x~2+10/3x+5/3=0. Based on the relationship between the root and the coefficient, the two root equations can be set to -5/3+k, -5/3-k (k≥0),