$\frac{5}{24}$ + $\frac{2}{3}$ + $\frac{3}{4}$
= $\frac{5}{24}$ + $\frac{2.8}{3.8}$ + $\frac{3.6}{4.6}$
= $\frac{5}{24}$ + $\frac{16}{24}$ + $\frac{18}{24}$
= $\frac{5+16+18}{24}$
= $\frac{39}{24}$
= $\frac{13}{8}$
$\frac{7}{10}$ + $\frac{13}{18}$ + $\frac{-19}{45}$
= $\frac{7.9}{10.9}$ + $\frac{13.5}{18.5}$ + $\frac{-19.2}{45.2}$
= $\frac{63}{90}$ + $\frac{65}{90}$ + $\frac{-38}{90}$
= $\frac{63+65-38}{90}$ = $\frac{90}{90}$
= $1$
