There is a simple fraction, if the numerator is added 1, the numerator is 2 less than the denominator; if the denominator is added 1, the fraction value is equal to (1/2), what is the original fraction.
有一个最简分数，如果分子加1，分子则比分母少2；如果分母加1，则分数值等于(1/2)，原分数是多少．
<gadget id="calculator">4 + 1 + 2</gadget>
<output>7</output>

<gadget id="calculator">4 / 7</gadget>
<output>4/7 = around 0.571429</output>

<result>4/7 = around 0.571429</result>