120/169 * 13/16 + 200/243 ÷ 100/81 - 1/13 * 10 =
Сокращаем 169 и 13 на 13; 120 и 16 на 8;
15/13• 1/2+ 200/243• 81/100- 10/13=
Сокращаем 200 и 100 на 109; 243 и 81 на 81;
15/13• 1/2+ 2/3• 1/1- 10/13=
15/26+ 2/3- 10/13=
(15•3)/(26•3) = (2•26)/(3•26) -(10•6)/(13•6)=
30/78+ 52/78- 60/78=
82/78- 60/78=
22/78=
Сокращаем на 2
= 11/39