53. Решите уравнение: 1) 25/27 x = 5/18; 2) 13/17 x = 39; 3) 4x = 5/7; 4) x : 2 2/15 = 1 9/16; 5) 4 4/9 : x = 5/27; 6) 1 4/9 x = 5,2.

1. x = 5/18 : 25/27 = 5/18 · 27/25 = 3/10.

2. x = 39 : 13/17 = 39 · 17/13 = 51.

3. x = 5/7 : 4 = 5/28.

4. x = 1 9/16 · 2 2/15 = 25/16 · 32/15 = 10/3.

5. 4 4/9 : x = 5/27, поэтому x = 4 4/9 : 5/27 = 40/9 · 27/5 = 24.

6. x = 5,2 : 1 4/9 = 5,2 : 13/9 = 5,2 · 9/13 = 3,6.

Ответ: 1) 3/10; 2) 51; 3) 5/28; 4) 10/3; 5) 24; 6) 3,6.