Both Xiao Min and Xiao Gang are stamp collectors. Xiao Min’s current stamps are 3/4 of Xiao Gang’s stamps. If Xiao Gang gives Xiao Min 9 stamps, then the two of them will have the same number of stamps. Do you know how many stamps Xiao Gang has? ? (solution with equation)
小敏和小刚都是集邮爱好者．小敏现在的邮票张数是小刚邮票张数的(3/4)，如果小刚给小敏9张邮票，那么他们两人的邮票张数就相等，你知道小刚有多少张邮票吗？(用方程解答)
<gadget id="calculator">9 + 9</gadget>
<output>18</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">18 / (1/4)</gadget>
<output>72</output>

<result>72</result>