diff --git a/Notebooks/Chap07/7_2_Backpropagation.ipynb b/Notebooks/Chap07/7_2_Backpropagation.ipynb
index ffc0b80..3e0c65b 100644
--- a/Notebooks/Chap07/7_2_Backpropagation.ipynb
+++ b/Notebooks/Chap07/7_2_Backpropagation.ipynb
@@ -4,7 +4,7 @@
   "metadata": {
     "colab": {
       "provenance": [],
-      "authorship_tag": "ABX9TyPOadzPTZy+kvsBZs5D7n5M",
+      "authorship_tag": "ABX9TyOlKB4TrCJnt91TnHOrfRSJ",
       "include_colab_link": true
     },
     "kernelspec": {
@@ -259,13 +259,13 @@
         "    # REPLACE THIS LINE\n",
         "    all_dl_dweights[layer] = np.zeros_like(all_weights[layer])\n",
         "\n",
-        "    # TODO: calculate the derivatives of the loss with respect to th eactivations from weight and derivatives of next preactivations (eq 7.20)\n",
+        "    # TODO: calculate the derivatives of the loss with respect to the activations from weight and derivatives of next preactivations (second part of last line of eq 7.24)\n",
         "    # REPLACE THIS LINE\n",
         "    all_dl_dh[layer] = np.zeros_like(all_h[layer])\n",
         "\n",
         "\n",
         "    if layer > 0:\n",
-        "      # TODO Calculate the derivatives of the loss with respect to the pre-activation f with respect to activation h (deriv of ReLu function)\n",
+        "      # TODO Calculate the derivatives of the loss with respect to the pre-activation f (use deriv of ReLu function, first part of last line of eq. 7.24)\n",
         "      # REPLACE THIS LINE\n",
         "      all_dl_df[layer-1] = np.zeros_like(all_f[layer-1])\n",
         "\n",