Answer:

Explanation:
Multiplicative Inverse of
=

Multiplicative inverse of any number is the reciprocal of that number.
Additive inverse of
=

Additive Inverse of any number is the number that has the opposite sign.
Solution:
![\sf (2)/(7) / - (21)/(8) \\\\(2)/(7) * - (8)/(21) \\\\= (2*(-8))/(7*21) \\\\= (-16)/(147) \\\\\rule[225]{225}{2}](https://img.qammunity.org/2021/formulas/mathematics/high-school/bhsfysvst8qkoh9xoqde7gtdx8vm4mywzo.png)
Hope this helped!
~AH1807