diff --git a/Chapter5/DeterminantsViaRowReduction.md b/Chapter5/DeterminantsViaRowReduction.md
index db3b26ae603da65eca49290443d6d2b2b0a9561e..a6629ad587d61d94a66558e8b7361d862fff3416 100644
--- a/Chapter5/DeterminantsViaRowReduction.md
+++ b/Chapter5/DeterminantsViaRowReduction.md
@@ -557,7 +557,14 @@ $$
\det{(A+B)} = \det{A}+\det{B}.
$$
-This statement is false. A trivial counterexample: $A = I$, $B = -I$.
+This statement is false. A trivial counterexample is given by $A = B = I_n$, for $n \geq 2$. Namely, for these matrices we see that
+
+<BR>
+
+$$
+ \det{A} + \det{B} = 1 + 1 = 2 \neq \det{(A+B)} = \det{(2I)} = 2^n.
+$$
+
</li>
<li>
diff --git a/Chapter7/LeastSquares.md b/Chapter7/LeastSquares.md
index 915c97a0e065b662d23641ad0ba1c8bf054828e7..d59d8d9d5c143656207778050b1cbaeb30749e62 100644
--- a/Chapter7/LeastSquares.md
+++ b/Chapter7/LeastSquares.md
@@ -1117,10 +1117,9 @@ give a unique least squares solution, and it is $\hat{a} = 1.6$, $\hat{b} = 0.3
:::{figure} Images/Fig-LeastSquares-LSline.svg
:name: Fig:LeastSquares:LSline
-Least square line
-:::
-
+Least squares line
+:::
For the line $y = \hat{a} + \hat{b}x$ the sum of the squares of the residues becomes