63. Вычислите: 1) (4/7)a : (16/23), a = 7; 2) (3/5)a : (6/7), a = −5; 3) (4/9)a · (1/11), a = −11; 4) (11/15) · (10/11)a, a = 2; 5) (15/17)a : (7/17), a = −1; 6) (3/13)a : (5/13), a = 4; 7) (5/9) · (7/10)a, a = 3; 8) (1/3)a : (4/9), a = −5; 9) (8/17)a · (51/16), a = −2; 10) (51/50)a : (17/100), a = 10; 11) (7/11) · (121/126)a, a = 5; 12) (5/12)a · (3/5), a = −4.

1. \(\frac47\cdot7:\frac{16}{23}=4\cdot\frac{23}{16}=\frac{23}{4}\).
2. \(\frac35\cdot(-5):\frac67=-3\cdot\frac76=-\frac72\).
3. \(\frac49\cdot(-11)\cdot\frac1{11}=-\frac49\).
4. \(\frac{11}{15}\cdot\frac{10}{11}\cdot2=\frac43\).
5. \(\frac{15}{17}\cdot(-1):\frac7{17}=-\frac{15}{7}\).
6. \(\frac3{13}\cdot4:\frac5{13}=\frac{12}{5}\).
7. \(\frac59\cdot\frac7{10}\cdot3=\frac76\).
8. \(\frac13\cdot(-5):\frac49=-\frac{15}{4}\).
9. \(\frac8{17}\cdot(-2)\cdot\frac{51}{16}=-3\).
10. \(\frac{51}{50}\cdot10:\frac{17}{100}=60\).
11. \(\frac7{11}\cdot\frac{121}{126}\cdot5=\frac{55}{18}\).
12. \(\frac5{12}\cdot(-4)\cdot\frac35=-1\).

Ответ: 23/4; −7/2; −4/9; 4/3; −15/7; 12/5; 7/6; −15/4; −3; 60; 55/18; −1.