First use the formula containing a and b to express the quotient of dividing 5 times the cube of the difference between a and b by the difference between the cubes of a and b, then find the value of this formula when a=7 and b=2?
先用含a、b的式子表示a与b的差的立方的5倍除以a、b两数立方差的商，再求a=7、b=2时这个式子的值是多少？
<gadget id="calculator">7 - 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 3</gadget>
<output>125</output>

<gadget id="calculator">7 ** 3</gadget>
<output>343</output>

<gadget id="calculator">2 ** 3</gadget>
<output>8</output>

<gadget id="calculator">343 - 8</gadget>
<output>335</output>

<gadget id="calculator">5 / 335</gadget>
<output>1/67 = around 0.014925</output>

<gadget id="calculator">125 * (1/67)</gadget>
<output>125/67 = around 1.865672</output>

<result>125/67 = around 1.865672</result>