Question

Find the sum of additive inverse and multiplicative inverse of $\frac{2}{5}$. [ 2 marks]

Answer 1

Given number: $\frac{2}{5}$

Additive inverse of $\frac{2}{5}=-\frac{2}{5}$
[0.5 mark]

Multiplicative inverse of $\frac{2}{5}=\frac{5}{2}$
[0.5 mark]


$\therefore$ Sum $=(-\frac{2}{5})+\left(\frac{5}{2}\right)=\frac{(-2\times 2)+5\times 5}{10}$

$=\frac{-4+25}{10}$

$=\frac{21}{10}$
[1 mark]

Hence, the sum of additive inverse and multiplicative inverse of $\frac{2}{5}$ is $\frac{21}{10}$.