There is a two-digit number, if you add "5" to its left, you get number A; if you add "5" to its right, you get B. It is known that the number B is 72 less than the number A, what is the two-digit number
有一个两位数，如果在它的左边添上"5"，就得到甲数；如果在它的右边添上"5"就得到乙．已知乙数比甲数少72，这个两位数是多少
<gadget id="calculator">500 - 5 - 72</gadget>
<output>423</output>

<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">423 / 9</gadget>
<output>47</output>

<result>47</result>