For a road, the repaired length is 3/7 of the unrepaired length, and the repaired length is 140 meters less than the unrepaired length. How many meters is the total length of this road?
一条路，已修长度是未修长度的(3/7)，已修长度比未修长度少140米，这条路全长多少米？
<gadget id="calculator">3 + 7</gadget>
<output>10</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(7/10) - (3/10)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">140 / (2/5)</gadget>
<output>350</output>

<result>350</result>