The product of the numbers A and B is 2500, and the number A is 4 times the number B, what is the difference between the numbers A and B?
甲、乙两数之积为2500，甲数是乙数的4倍，则甲、乙两数之差是多少．
<gadget id="calculator">4 * 25</gadget>
<output>100</output>

<gadget id="calculator">100 - 25</gadget>
<output>75</output>

<result>75</result>