Question

Express $\frac{13}{-8}$ as a rational number with denominator

(i) −40
(ii) 32

Answer 1

(i) Denominator of $\frac{13}{-8}$ is −8.
​Clearly, (−8)×5= −40
Multiplying both the numerator and the denominator by 5:
$\begin{array}{l}\frac{13\times 5}{-8\times 5}=\frac{65}{-40}\\ \\ \frac{13}{-8}=\frac{65}{-40}\end{array}$


(ii) Denominator of $\frac{13}{-8}$ is −8.
Clearly, (−8)×(−4)= 32
Multiplying both the numerator and the denominator by −4:

$\frac{13\times (-4)}{-8\times (-4)}=\frac{-52}{32}$

$\frac{13}{-8}$=$\frac{-52}{32}$