diff --git a/01_fundamentals.tex b/01_fundamentals.tex
index 0952adb19827c5131870e5b5c4da3f42abaef31f..e0d9ba23e7c03867524a7fd19ea5f9bcbcbb48b9 100644
--- a/01_fundamentals.tex
+++ b/01_fundamentals.tex
@@ -50,6 +50,6 @@ For doners we have:
 Every semiconductor is neutral,
 which imposes the following condition:
 \begin{equation}
-    P_0-n_0+N_d + N_a = 0
+    P_0-n_0 + N_d - N_a = 0
 \end{equation}
 where $p_0n_0=n_i^2$.
\ No newline at end of file
diff --git a/02_carrier_transport.tex b/02_carrier_transport.tex
index 51d5be0abbde6174d71ace8867bad6b9f0ca8571..d068b2bd82a90265889bbc0d1aef9970b86a8a60 100644
--- a/02_carrier_transport.tex
+++ b/02_carrier_transport.tex
@@ -8,7 +8,7 @@ but heres the probability distribution:
     f(E) = \frac{1}{1+e^{(E-E_F)/kT}}
 \end{equation}
 
-Electron concentration in conductance band:
+Electron concentration in conduction band:
 \begin{equation}
     n=N_ce^{-(E_c-E_f)/kT}
 \end{equation}
@@ -62,8 +62,11 @@ For the sake of simplicity, let's define mobility for both holes and electrons.
 \subsection{Drift current}
 For the net drift current density slap together velocity, density and charge.
 \begin{equation}
-    label{eq:drift_current}
-    J^{drift} = J_n^{drift}+J_p^{drift} = q(n\mu_n+p\mu_p)E
+    \label{eq:drift_current}
+    \begin{split}
+        J^{drift} &= J_n^{drift}+J_p^{drift} \\
+        &= q(n\mu_n+p\mu_p)E
+    \end{split}
 \end{equation}
 From which we can  find Ohm's law:
 \begin{alignat}{2}