After the math teacher takes out a red ball from a pocket containing several red and blue balls, (1/7) of the remaining balls in the bag are red balls; After 2 blue balls, (1/5) of the remaining balls in the bag are red balls, so how many small balls are there in the bag?
数学老师从一个装有若干个红色和蓝色小球的口袋中取出1个红色小球后，袋中剩下的小球有(1/7)是红色小球；如果一开始从口袋中取出2个蓝色小球后，袋中剩下的小球就有(1/5)是红色小球，那么原来这个口袋中有多少个小球．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(2/5) - (1/7)</gadget>
<output>9/35 = around 0.257143</output>

<gadget id="calculator">1 + (9/35)</gadget>
<output>44/35 = around 1.257143</output>

<gadget id="calculator">(1/5) - (1/7)</gadget>
<output>2/35 = around 0.057143</output>

<gadget id="calculator">(44/35) / (2/35)</gadget>
<output>22</output>

<result>22</result>