If X is added to the numerator and denominator of the fraction (1/5), the fraction becomes (2/3), what is the value of X?
若分数(1/5)的分子、分母各加X，分数变成(2/3)，则X的值是多少．
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/3) * 5</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">(10/3) - 1</gadget>
<output>7/3 = around 2.333333</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(7/3) / (1/3)</gadget>
<output>7</output>

<result>7</result>