Two cars, passenger and freight, are traveling towards each other from places A and B at the same time. When the passenger car travels (3/4) of the whole journey, the truck travels (3/5) of the whole journey. At this time, the distance between the two cars is 42 kilometers. How many kilometers are there between A and B?
客、货两车分别同时从甲、乙两地相向而行，当客车行了全程的(3/4)时，货车行了全程的(3/5)，这时两车相距42千米，甲、乙两地相距多少千米？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/5) - 1</gadget>
<output>-2/5 = around -0.4</output>

<gadget id="calculator">(3/4) + (-2/5)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">42 / (7/20)</gadget>
<output>120</output>

<result>120</result>