1 вычислите а)2\3*4\5 б)3\7 *7\8 в) 11\12 *8\9 г)(2\3)во второй д)2\3:5\7 е) 9\16 :3\2 ж)3\4:4 з)3:3\9 2 вычислите а) 2*(12\25:6\5) б) 14\15:2\3*10\21 в) 2\3*3\4*4\5*5\6

14,6:7,3 умножить (-16)-2,8 умножить (-4,5):14=

1. а) 2/3 * 4/5 = 8/15 б) 3/7 * 7/8 = 3/1 * 1/8 = 3/8 в) 11/12 * 8/9 = 11/3 * 2/9 = 22/27 г) (2/3)^2 = 2/3 * 2/3 = 4/9 д) 2/3 : 5/7 = 2/3 * 7/5 = 14/15 е) 9/16 : 3/2 = 9/16 * 2/3 = 3/8 * 1/1 = 3/8  ж) 3/4 : 4 = 3/4 : 4/1 = 3/4 * 1/4 = 3/16 з) 3 : 3/9 = 3/1 : 3/9 = 3/1 : 9/3 = 27/3 = 9   2. а) 2 * (12/25 : 6/5) = 0,8   1. 12/25 : 6/5 = 12/25 * 5/6 = 2/5 * 1/1 = 2/5 = 0,4 2. 2 * 0,4 = 2/1 * 4/10 = 1/1 * 4/5 = 4/5 = 0,8   б) 14/15 : 2/3 * 10/21 = 2/3   1. 14/15 : 2/3 = 14/15 * 3/2 = 7/5 * 1/1 = 7/5 2. 7/5 * 10/21 = 1/1 * 2/3 = 2/3   в) 2/3 * 3/4 * 4/5 * 5/6 = (2 * 3 * 4 * 5) : (3 * 4 * 5 * 6) = 120/360 = 1/3

№1

а) 2/3 * 4/5 = 8/15;

б) 3/7 * 7/8 = 3/8;

в) 11/12 * 8/9 = 22/27;

г) (2/3)² = 2/3 * 2/3 = 4/9;

д) 2/3 : 5/7 = 2/3 * 7/5 = 14/15;

е) 9/16 : 3/2 = 9/16 * 2/3 = 3/8;

ж) 3/4 : 4 = 3/4 * 1/4 = 3/16;

з) 3 : 3/9 = 3 * 9/3 = 9.

 

№2

а) 2 * (12/25 : 6/5) = 2 * (12/25 * 5/6) = 2 * 2/5 = 4/5.

Ответ: 2 * (12/25 : 6/5) = 4/5.

б) 14/15 : 2/3 * 10/21 = 14/15 * 3/2 * 10/21 = 7/5 * 10/21 = 2/3.

Ответ: 14/15 : 2/3 * 10/21 = 2/3.

в) 2/3 * 3/4 * 4/5 * 5/6 = 1/2 * 4/5 * 5/6 = 2/5 * 5/6 = 1/3.

Ответ: 2/3 * 3/4 * 4/5 * 5/6 = 1/3.