diff --git a/content/blog/1d-collisions/index.md b/content/blog/1d-collisions/index.md
index dcb4b57..106d539 100644
--- a/content/blog/1d-collisions/index.md
+++ b/content/blog/1d-collisions/index.md
@@ -2,12 +2,8 @@ $$ m_{1}\vec{v}_{1} + m_{2}\vec{v}_{2} = m_{1}\vec{v'}_{1} + m_{2}\vec{v'}_{2} $
 
 $$ \frac{m_{1}{v_{1}}^2}{2} + \frac{m_{2}{v_{2}}^2}{2} = \frac{m_{1}{v'_{1}}^2}{2} + \frac{m_{2}{v'_{2}}^2}{2} $$
 
-$$ \left\{
-\begin{array}{lr}
-m_{1}({v_{1}} - {v'_{1}}) = m_{2}({v'_{2}} - {v_{2}})\\
-m_{1}({v_{1}}^2 - {v'_{1}}^2) = m_{2}({v'_{2}}^2 - {v_{2}}^2)
-\end{array}
-\right. $$
+$$\begin{cases}m_{1}({v_{1}} - {v'_{1}}) = m_{2}({v'_{2}} - {v_{2}})\\m_{1}({v_{1}}^2 - {v'_{1}}^2) = m_{2}({v'_{2}}^2 - {v_{2}}^2)
+\end{cases}$$
 
 $$ \frac{v_{1} - v'_{1}}{{v_{1}^2} - {v'_{1}}^2} = \frac{v'_{2} - v_{2}}{{{v'_{2}}^2} - {v_{2}}^2} $$
 
@@ -17,23 +13,17 @@ $$ \frac{1}{v_1 + v'_1} = \frac{1}{v'_2 + v_2} $$
 
 $$ v_1 + v'_1 = v'_2 + v_2 $$
 
-$$ \left\{
-\begin{array}{lr}
+$$\begin{cases}
 v'_1 = v_2 + v'_2 - v_1\\
 v'_2 = v_1 + v'_1 - v_2
-\end{array}
-\right. $$
+\end{cases}$$
 
-$$ \left\{
-\begin{array}{lr}
+$$ \begin{cases}
 m_1v_1 + m_2v_2 = m_1{v'}_1 + m_2(v_1 + {v'}_1 - v_2)\\
 m_1v_1 + m_2v_2 = m_1(v_2 + v'_2 - v_1) + m_2v'_2
-\end{array}
-\right. $$
+\end{cases} $$
 
-$$ \left\{
-\begin{array}{lr}
+$$ \begin{cases}
 v'_1 = \frac{2m_2v_2 + v_1(m_1-m_2)}{m_1+m_2}\\
 v'_2 = \frac{2m_1v_1 + v_2(m_2-m_1)}{m_1+m_2}
-\end{array}
-\right. $$
+\end{cases} $$