Ginkgo trees can live 2,000 years, 400 years more than twice as long as camphor trees. How old is the life span of camphor trees? (solution by equation)
银杏树能活2000岁，比樟树的2倍还多400岁，樟树的寿命是多少岁？(用方程解)
<gadget id="calculator">2_000 - 400</gadget>
<output>1_600</output>

<gadget id="calculator">1_600 / 2</gadget>
<output>800</output>

<result>800</result>