a)MSC:120
$\frac{7}{40}= \frac{7.3}{120}= \frac{21}{120}$
b)MSC:1898
$\frac{24}{146}= \frac{24.13}{1898}= \frac{312}{1898}$
$\frac{6}{13}= \frac{6.146}{1898}= \frac{876}{1898}$
c)MSC:120
$\frac{7}{30}= \frac{7.4}{120}= \frac{28}{120}$
$\frac{13}{60}= \frac{13.2}{120}= \frac{26}{120}$
$\frac{-9}{40}= \frac{-9.3}{120}= \frac{-27}{120}$
d)MSC:1080
$\frac{17}{60}= \frac{17.18}{1080}= \frac{306}{1080}$
$\frac{-5}{18}= \frac{-5.60}{1080}= \frac{-300}{1080}$
$\frac{-64}{90}= \frac{-64.12}{1080}= \frac{-768}{1080}$
