Выполним действия:
- a) ($$\frac{4}{9}$$ + $$\frac{7}{36}$$) $$\cdot$$ 36 = ($$\frac{4 \cdot 4}{9 \cdot 4}$$ + $$\frac{7}{36}$$) $$\cdot$$ 36 = ($$\frac{16}{36}$$ + $$\frac{7}{36}$$) $$\cdot$$ 36 = $$\frac{16+7}{36}$$ $$\cdot$$ 36 = $$\frac{23}{36}$$ $$\cdot$$ 36 = 23
- б) ($$\frac{17}{18}$$ - $$\frac{5}{6}$$) $$\cdot$$ 18 = ($$\frac{17}{18}$$ - $$\frac{5 \cdot 3}{6 \cdot 3}$$) $$\cdot$$ 18 = ($$\frac{17}{18}$$ - $$\frac{15}{18}$$) $$\cdot$$ 18 = $$\frac{17-15}{18}$$ $$\cdot$$ 18 = $$\frac{2}{18}$$ $$\cdot$$ 18 = 2
- в) ($$\frac{5}{12}$$ + $$\frac{11}{18}$$) $$\cdot$$ 36 = ($$\frac{5 \cdot 3}{12 \cdot 3}$$ + $$\frac{11 \cdot 2}{18 \cdot 2}$$) $$\cdot$$ 36 = ($$\frac{15}{36}$$ + $$\frac{22}{36}$$) $$\cdot$$ 36 = $$\frac{15+22}{36}$$ $$\cdot$$ 36 = $$\frac{37}{36}$$ $$\cdot$$ 36 = 37
- г) ($$\frac{10}{11}$$ - $$\frac{19}{33}$$) $$\cdot$$ 66 = ($$\frac{10 \cdot 3}{11 \cdot 3}$$ - $$\frac{19}{33}$$) $$\cdot$$ 66 = ($$\frac{30}{33}$$ - $$\frac{19}{33}$$) $$\cdot$$ 66 = $$\frac{30-19}{33}$$ $$\cdot$$ 66 = $$\frac{11}{33}$$ $$\cdot$$ 66 = 22
- д) ($$\frac{15}{24}$$ + $$\frac{7}{36}$$) $$\cdot$$ 12 = ($$\frac{15 \cdot 3}{24 \cdot 3}$$ + $$\frac{7 \cdot 2}{36 \cdot 2}$$) $$\cdot$$ 12 = ($$\frac{45}{72}$$ + $$\frac{14}{72}$$) $$\cdot$$ 12 = $$\frac{45+14}{72}$$ $$\cdot$$ 12 = $$\frac{59}{72}$$ $$\cdot$$ 12 = $$\frac{59}{6}$$ = 9$$\frac{5}{6}$$
- е) ($$\frac{25}{26}$$ - $$\frac{27}{65}$$) $$\cdot$$ 91 = ($$\frac{25 \cdot 5}{26 \cdot 5}$$ - $$\frac{27 \cdot 2}{65 \cdot 2}$$) $$\cdot$$ 91 = ($$\frac{125}{130}$$ - $$\frac{54}{130}$$) $$\cdot$$ 91 = $$\frac{125-54}{130}$$ $$\cdot$$ 91 = $$\frac{71}{130}$$ $$\cdot$$ 91 = $$\frac{71 \cdot 7}{10}$$ = $$\frac{497}{10}$$ = 49$$\frac{7}{10}$$ = 49,7
Ответ: a) 23; б) 2; в) 37; г) 22; д) 9$$\frac{5}{6}$$; е) 49,7