There is a batch of coal, (2/3) tons are used on the first day, and (1/5) tons are used less on the second day than on the first day, how many tons of coal are used in two days?
有一批煤，第一天用去(2/3)吨，第二天比第一天少用去(1/5)吨，两天一共用去多少吨煤？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(2/3) - (1/5)</gadget>
<output>7/15 = around 0.466667</output>

<gadget id="calculator">(2/3) + (7/15)</gadget>
<output>17/15 = around 1.133333</output>

<result>17/15 = around 1.133333</result>