diff --git a/2.LinearRegression.md b/2.LinearRegression.md
index 526ea54..b451e9d 100644
--- a/2.LinearRegression.md
+++ b/2.LinearRegression.md
@@ -54,8 +54,8 @@ $$
 $$
 \begin{align}
 L(w)=\log p(Y|X,w)&=\log\prod\limits_{i=1}^Np(y_i|x_i,w)\nonumber\\
-&=\sum\limits_{i=1}^N\log(\frac{1}{\sqrt{2\pi\sigma}}e^{-\frac{(y_i-w^Tx_i)^2}{2\sigma^2}})\\
-\mathop{argmax}\limits_wL(w)&=\mathop{argmin}\limits_w\sum\limits_{i=1^N}(y_i-w^Tx_i)^2
+&=\sum\limits_{i=1}^N\log(\frac{1}{\sqrt{2\pi}\sigma}e^{-\frac{(y_i-w^Tx_i)^2}{2\sigma^2}})\\
+\mathop{argmax}\limits_wL(w)&=\mathop{argmin}\limits_w\sum\limits_{i=1}^N(y_i-w^Tx_i)^2
 \end{align}
 $$
 这个表达式和最小二乘估计得到的结果一样。