矩阵的概念
矩阵的加法和减法
重要程度：8 分
<div>
<h2>矩阵的加法</h2>
<p>两个同型矩阵相加，即它们的行数和列数都相同，相加时将对应的元素相加。</p>
<h3>举例说明：</h3>
<p>设矩阵A和B如下：</p>
<table border="1">
<tr>
<td>A = </td>
<td>1</td>
<td>2</td>
</tr>
<tr>
<td></td>
<td>3</td>
<td>4</td>
</tr>
</table>
<table border="1">
<tr>
<td>B = </td>
<td>5</td>
<td>6</td>
</tr>
<tr>
<td></td>
<td>7</td>
<td>8</td>
</tr>
</table>
<p>则矩阵A和B的和为：</p>
<table border="1">
<tr>
<td>A + B = </td>
<td>1+5</td>
<td>2+6</td>
</tr>
<tr>
<td></td>
<td>3+7</td>
<td>4+8</td>
</tr>
</table>
<p>即：</p>
<table border="1">
<tr>
<td>A + B = </td>
<td>6</td>
<td>8</td>
</tr>
<tr>
<td></td>
<td>10</td>
<td>12</td>
</tr>
</table>
<h2>矩阵的减法</h2>
<p>两个同型矩阵相减，即将一个矩阵的每个元素减去另一个矩阵对应位置的元素。</p>
<h3>举例说明：</h3>
<p>设矩阵C和D如下：</p>
<table border="1">
<tr>
<td>C = </td>
<td>9</td>
<td>8</td>
</tr>
<tr>
<td></td>
<td>7</td>
<td>6</td>
</tr>
</table>
<table border="1">
<tr>
<td>D = </td>
<td>4</td>
<td>3</td>
</tr>
<tr>
<td></td>
<td>2</td>
<td>1</td>
</tr>
</table>
<p>则矩阵C和D的差为：</p>
<table border="1">
<tr>
<td>C - D = </td>
<td>9-4</td>
<td>8-3</td>
</tr>
<tr>
<td></td>
<td>7-2</td>
<td>6-1</td>
</tr>
</table>
<p>即：</p>
<table border="1">
<tr>
<td>C - D = </td>
<td>5</td>
<td>5</td>
</tr>
<tr>
<td></td>
<td>5</td>
<td>5</td>
</tr>
</table>
</div>