45 plus (2/7) of a certain number is exactly equal to the largest two-digit number. Find a certain number.
45加上某数的(2/7)，正好等于最大的两位数，求某数．
<gadget id="calculator">99 - 45</gadget>
<output>54</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">54 / (2/7)</gadget>
<output>189</output>

<result>189</result>