7. Вычислите 2$$\frac{16}{25}$$\cdot$$($$\frac{2}{3}$$+$$\frac{7}{12}$$)$$\cdot$$\frac{9}{10}$$:1$$\frac{15}{16}$$

7. Вычислите 2$$\frac{16}{25}$$\cdot$$($$\frac{2}{3}$$+$$\frac{7}{12}$$)$$\cdot$$\frac{9}{10}$$:1$$\frac{15}{16}$$

1) $$\frac{2}{3}$$+$$\frac{7}{12}$$ =$$\frac{2\cdot4 + 7}{12}$$=$$\frac{8+7}{12}$$=$$\frac{15}{12}$$

2) 2$$\frac{16}{25}$$\cdot$$($$\frac{15}{12}$$)=$$\frac{2\cdot25+16}{25}$$\cdot$$($$\frac{15}{12}$$)=$$\frac{66}{25}$$\cdot$$($$\frac{15}{12}$$)=$$\frac{66\cdot15}{25\cdot12}$$=$$\frac{990}{300}$$

3) 1$$\frac{15}{16}$$=$$\frac{1\cdot16+15}{16}$$=$$\frac{31}{16}$$

4) $$\frac{990}{300}$$\cdot$$\frac{9}{10}$$:$$\frac{31}{16}$$=$$\frac{990}{300}$$\cdot$$\frac{9}{10}$$\cdot$$\frac{16}{31}$$=$$\frac{990\cdot9\cdot16}{300\cdot10\cdot31}$$=$$\frac{142560}{93000}$$

Ответ: $$\frac{142560}{93000}$$