Find the sum of additive inverse and multiplicative inverse of $\frac{7}{3}$.

If $-38\times \frac{-7}{19}=\frac{-7}{19}\times k$, then $k=$_____.

If $\frac{-23}{17}\times \frac{18}{35}=\frac{18}{35}\times k$, then $k=$_____.

$\frac{-12}{5}\times \left(\frac{4}{15}\times -\frac{25}{16}\right)=\left(\frac{-12}{5}\times \frac{4}{15}\right)\times$_____

$\left(\frac{-3}{17}\right)+\left(\frac{-12}{5}\right)=\left(\frac{-12}{5}\right)+$ ($-\frac{1}{17}\times$_____)

$\frac{-16}{7}+$ (_____) $=\frac{-16}{7}$

If $\left(\frac{15}{7}\times \frac{-21}{10}\right)\times \frac{-5}{6}=k\times \left(\frac{-21}{10}\times \frac{-5}{6}\right)$, then $k=$_____.

The reciprocal of a positive rational number is _____. (positive/negative)

$-9+\frac{-21}{8}=$ (_____) $+(-9)$

$-12+\left(\frac{7}{12}+\frac{-9}{11}\right)=\left(-12+\frac{7}{12}\right)+$ (_____)