21 целая4/15 + 1 целая5/6 - 9 целых 7/30 + 16целых7/24=?

Решите задачу:

$21 \frac{4}{15} +1 \frac{5}{6} -9 \frac{7}{30} +16 \frac{7}{24} =30 \frac{19}{120}$

$1)21 \frac{4}{15} +1 \frac{5}{6} =21 \frac{8}{30} +1 \frac{25}{30} =22 \frac{33}{30} =23 \frac{3}{30}=23 \frac{1}{10} =23,1$

$2)23 \frac{1}{10} -9 \frac{7}{30} = 23\frac{3}{30} -9 \frac{7}{30} =22 \frac{33}{30} -9 \frac{7}{30} = 13\frac{26}{30} =13 \frac{13}{15}$

$3) 13\frac{13}{15} +16 \frac{7}{24} =13 \frac{104}{120} +16 \frac{35}{120} =29 \frac{139}{120} =30 \frac{19}{120}$