A and B jointly build a road. A has repaired 1/5 of the full length, B has repaired 450 meters, and the remaining half has not been repaired. How many meters is the total length of this road?
甲和乙合修一条公路，甲修了全长的(1/5)，乙修了450米，还剩下一半没修，这条公路全长多少米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/2) - (1/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">450 / (3/10)</gadget>
<output>1_500</output>

<result>1_500</result>