The length of a rectangle is 5 meters and the width is 3 meters. If both the length and width are reduced by 1 meter, how many square meters is the area reduced?
长方形长5米，宽3米，如果长和宽都减少1米，面积减少了多少平方米
<gadget id="calculator">5 * 3</gadget>
<output>15</output>

<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">15 - 8</gadget>
<output>7</output>

<result>7</result>