例題 次の行列の和$A+B$を求めよ.

$\displaystyle A = \left(\begin{array}{rr}
2&-3\\
4&2
\end{array}\right), \ \ \ B = \left(\begin{array}{rr}
-1&2\\
3&0
\end{array}\right ) $

解答 行列の和は対応する成分の和:

$A + B = \left(\begin{array}{rr}
2&\!\!-3\\
4&\!\!2
\end{array}\right) + \left(...
...ay}\right) = \left(\begin{array}{rr}
1&\!\!-1\\
7&\!\!2
\end{array}\right ) . $