Обчисли:
1)$\frac{2}{9}$ + $\frac{3}{5}$;
2) $\frac{4}{9}$ +$\frac{1}{6}$;
3) $\frac{1}{18}$ + $\frac{5}{12}$;
4) $\frac{3}{10}$ + $\frac{2}{15}$;
5) $\frac{6}{7}$ - $\frac{2}{3}$;
6) $\frac{11}{12}$ - $\frac{5}{6}$;
7) $\frac{7}{12}$ - $\frac{3}{8}$;
8) $\frac{9}{14}$ - $\frac{17}{35}$.
Розв'язок:
1) $\frac{2}{9}$ + $\frac{3}{5}$ = $\frac{10+27}{45}$ = $\frac{37}{45}$;
2) $\frac{4}{9}$ + $\frac{1}{6}$ = $\frac{8+3}{18}$ = $\frac{11}{18}$;
3) $\frac{1}{18}$ + $\frac{5}{12}$ = $\frac{2+15}{36}$ = $\frac{17}{36}$;
4) $\frac{3}{10}$ + $\frac{2}{15}$ = $\frac{9+4}{30}$ = $\frac{13}{30}$;
5) $\frac{6}{7}$ – $\frac{2}{3}$ = $\frac{18–14}{21}$ = $\frac{4}{21}$;
6) $\frac{11}{12}$ – $\frac{5}{6}$ = $\frac{11–10}{12}$ = $\frac{1}{12}$;
7) $\frac{7}{12}$ – $\frac{3}{8}$ = $\frac{14–9}{24}$ = $\frac{5}{24}$;
8) $\frac{9}{14}$ – $\frac{17}{35}$ = $\frac{45–34}{70}$ = $\frac{11}{70}$.