Вычислите: (3/4 − 1/6) · 3; (1/6 + 1/4) · 9; (2/5 + 13/15) · 6; (1/5 + 8/15) · 6; (9/10 − 7/15) · 3.

1. \(\left(\frac34-\frac16\right)\cdot3=\frac7{12}\cdot3=\frac74\)
2. \(\left(\frac16+\frac14\right)\cdot9=\frac5{12}\cdot9=\frac{15}{4}\)
3. \(\left(\frac25+\frac{13}{15}\right)\cdot6=\frac{19}{15}\cdot6=\frac{38}{5}\)
4. \(\left(\frac15+\frac8{15}\right)\cdot6=\frac{11}{15}\cdot6=\frac{22}{5}\)
5. \(\left(\frac9{10}-\frac7{15}\right)\cdot3=\frac{13}{30}\cdot3=\frac{13}{10}\)

Ответ: 7/4; 15/4; 38/5; 22/5; 13/10.