Solution 3c 10

Suppose $A$ is an m-by-n matrix and $C$ is an n-by-p matrix. Prove that

(AC)_{j,\cdot} = A_{j,\cdot} C

for $1 \le j \le m$ . In other words, show that row $j$ of $AC$ equals (row $j$ of $A$ ) times $C$ .

TODO