Fix typo

Fix typos introduces more

pages/Math429/Math429_L10.md

@@ -35,7 +35,7 @@ Suppose $V,W$ are finite dimensional with $dim(V)>dim(W)$, then there are no inj
 
 Suppose $V,W$ are finite dimensional with $dim(V)<dim(W)$, then there are no surjective maps from $V$ to $W$.
 
-ideas of Proof: relies on **Theorem 3.21** $dim(null(T))>0$
+Ideas of Proof: relies on **Theorem 3.21** $dim(null(T))>0$
 
 ### Linear Maps and Linear Systems 3EX-1