There are two points M and N on the line segment AB. The point M divides the line segment into two parts of 5:7, and the point N divides the line segment AB into two parts of 5:11. If MN=22.5 cm, find the length of AB.
线段AB上有两点M、N，点M分线段为5：7两部分，点N分线段AB为5：11两部分，若MN=22.5厘米，求AB的长．
<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">5 + 11</gadget>
<output>16</output>

<gadget id="calculator">5 / 16</gadget>
<output>5/16 = around 0.3125</output>

<gadget id="calculator">(5/12) - (5/16)</gadget>
<output>5/48 = around 0.104167</output>

<gadget id="calculator">22.5 / (5/48)</gadget>
<output>216</output>

<result>216</result>