Solve the equations: Xiao Ming and Xiao Liang are practicing running on a 400-meter circular track. It is known that Xiao Ming’s speed is 7 meters per second, and Xiao Liang’s speed is Xiao Ming’s (5/7). Run, how many seconds will it take for them to meet for the first time after they start running?
列方程解应用题：小明和小亮在400米环形跑道练习跑步，已知小明的速度是每秒7米，小亮的速度是小明的(5/7)，两人同时同地同向而跑，他们起跑后第一次相遇需要多少秒？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">7 * (5/7)</gadget>
<output>5</output>

<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">400 / 2</gadget>
<output>200</output>

<result>200</result>