(7-6,35):6,5+9.9/(1,2:0,25-0,25-1.5/16):169/24

(7 - 6,35) : 6,5 + 9,9 : (1,2 : 0,25 - 0,25 - 1 5/16) : 169/24 = 1 291807/731770.

1) 7 - 6,35 = 7 - 6 - 0,35 = 1 - 0,35 = 0,65;

2) 0,65 : 6,5 = 65/100 : 65/10 = 65/100 * 10/65 = (65 * 10)/(10 * 10 * 65) = 1/10;

3) 1,2 : 0,25 = 12/10 : 25/10 = 12/10 * 10/25 = 12/25;

4) 12/25 - 0,25 = (12 * 4)/100 - 25/100 = 48/100 - 25/100 = 23/100;

5) 23/100 - 1 5/16 = 92/400 - 1 - 125/400 = -1 33/400;

6) 9,9 : (-1 33/400) = 99/10 * 400/433 = (99 * 40)/433 = 3960/433;

7) 3960/433 : 169/24 = 3960/433 * 24/169 = 95040/73177 = 1 21863/73177;

8) 1/10 + 1 21863/73177 = 1 + 73177/731770 + 218630/731770 = 1 291807/731770.