Question

Tick (✓) the correct answer
$\left(\frac{7}{-26}+\frac{16}{39}\right)=?$
(a) $\frac{11}{78}$
(b) $\frac{-11}{78}$
(c) $\frac{11}{39}$
(d) $\frac{-11}{39}$

Answer 1

$\frac{7}{-26}=\frac{-7}{26}$

Now, we have:

$\left(\frac{7}{-26}+\frac{16}{39}\right)=\left(\frac{-7}{26}+\frac{16}{39}\right)$

LCM of 26 and 39 is 1014, that is, $\left(29\times 1\times 36\right).$

(a) $\frac{11}{78}$
$\left(\frac{-7}{26}+\frac{16}{39}\right)=\frac{39\times \left(-7\right)+26\times 16}{1014}$
$$\begin{gathered} =\frac{\left(-273\right)+416}{1014} \\ =\frac{143}{1014} \\ =\frac{11}{78} \end{gathered}$$