Beibei drew a rectangle with a perimeter of 0.84 meters. It is known that the length of this rectangle is 0.3 meters. What is its width in meters? (Solving problems with equations)
贝贝画了一个周长是0.84米的长方形，已知这个长方形的长是0.3米，它的宽是多少米？(用方程解决问题)
<gadget id="calculator">0.3 * 2</gadget>
<output>0.6</output>

<gadget id="calculator">0.84 - 0.6</gadget>
<output>0.24</output>

<gadget id="calculator">0.24 / 2</gadget>
<output>0.12</output>

<result>0.12</result>