3. Выполните действия: a) (3$$\frac{5}{12}$$+4$$\frac{7}{12}$$)-5$$\frac{2}{9}$$; б)12$$\frac{2}{15}$$-(7$$\frac{11}{15}$$+2$$\frac{8}{15}$$).

3. Выполните действия:

1. a) (3$$\frac{5}{12}$$+4$$\frac{7}{12}$$)-5$$\frac{2}{9}$$=(3+4)+$$\frac{5+7}{12}$$-5$$\frac{2}{9}$$=7$$\frac{12}{12}$$-5$$\frac{2}{9}$$=7+1-5$$\frac{2}{9}$$=8-5$$\frac{2}{9}$$=7$$\frac{9}{9}$$-5$$\frac{2}{9}$$=(7-5)+$$\frac{9-2}{9}$$=2$$\frac{7}{9}$$
2. б) 12$$\frac{2}{15}$$-(7$$\frac{11}{15}$$+2$$\frac{8}{15}$$)=12$$\frac{2}{15}$$-((7+2)+$$\frac{11+8}{15}$$)=12$$\frac{2}{15}$$-(9$$\frac{19}{15}$$)=12$$\frac{2}{15}$$-(9+1$$\frac{4}{15}$$)=12$$\frac{2}{15}$$-10$$\frac{4}{15}$$=11$$\frac{17}{15}$$-10$$\frac{4}{15}$$=(11-10)+$$\frac{17-4}{15}$$=1$$\frac{13}{15}$$

Ответ: a) 2$$\frac{7}{9}$$; б) 1$$\frac{13}{15}$$