85 trees are planted on the side of a section of road, both ends are planted, and the distance between every two trees is 5 meters. How many meters is the length of this section of road?
在一段公路的一旁栽了85棵树，两头都栽，每两棵树之间相距5米，这段公路长多少米？
<gadget id="calculator">85 - 1</gadget>
<output>84</output>

<gadget id="calculator">5 * 84</gadget>
<output>420</output>

<result>420</result>