Question

Express as a rational number with denominator:
(i) 20
(ii) 36
(iii) 44
(iv) −80

Answer 1

3/4 as rational number with denominator:

(i)
$$\begin{gathered} 20\mathrm{is}: \\ \frac{3\times 5}{4\times 5}=\frac{15}{20}(\mathrm{multiplying}\mathrm{numerator}\mathrm{and}\mathrm{denominator}\text{by}5) \end{gathered}$$


(ii)
$$\begin{gathered} 36\mathrm{is}: \\ \frac{3\times 9}{4\times 9}=\frac{27}{36}(\mathrm{multiplying}\mathrm{numerator}\mathrm{and}\mathrm{denominator}\text{by}9) \end{gathered}$$


(iii)
$$\begin{gathered} 44\mathrm{is}: \\ \frac{3\times 11}{4\times 11}=\frac{33}{44}(\mathrm{multiplying}\mathrm{numerator}\mathrm{and}\mathrm{denominator}\text{by}11) \end{gathered}$$

(iv)
$$\begin{gathered} -80\mathrm{is}: \\ \frac{3\times -20}{4\times -20}=\frac{-60}{-80}(\mathrm{multiplying}\mathrm{numerator}\mathrm{and}\mathrm{denominator}\text{by}-20) \end{gathered}$$