\left.{\frac{\Delta k_i(t+1)}{k_i(t)}}\middle/ \frac{\Delta L(t+1)}{L(t)}=\frac{\Delta k_i(t+1)L(t)}{k_i(t)\Delta L(t+1)}\right.
$\left. AAA \middle/ BBB \right.$
latex大斜杠， 除号
latex大斜杠， 除号
\left.{\frac{\Delta k_i(t+1)}{k_i(t)}}\middle/ \frac{\Delta L(t+1)}{L(t)}=\frac{\Delta k_i(t+1)L(t)}{k_i(t)\Delta L(t+1)}\right.
$\left. AAA \middle/ BBB \right.$