Решение

1. a) 434 * 31 + 65 * 17;

   1. 434 * 31 = 13454
   2. 65 * 17 = 1105
   3. 13454 + 1105 = 14559

2. б) 179 800 : 29 – 72 * 78;

   1. 179 800 : 29 = 6200
   2. 72 * 78 = 5616
   3. 6200 – 5616 = 584

3. в) (607 - 427) * 84 : 36;

   1. 607 - 427 = 180
   2. 180 * 84 = 15120
   3. 15120 : 36 = 420

4. г) 68 * (256 + 144) : 340.

   1. 256 + 144 = 400
   2. 68 * 400 = 27200
   3. 27200 : 340 = 80