5.386 Вычислите: а) (2616 : 6 + 26 \(\cdot\) 14) : 4 – 196; б) (867 000 : 2125 – 396) \(\cdot\) 25; в) 30 \(\cdot\) 29 – 29 \(\cdot\) 28 + 28 \(\cdot\) 27 – 27 \(\cdot\) 26; г) (39² + 39) + (40² – 40).

Решение:

а) (2616 : 6 + 26 \(\cdot\) 14) : 4 – 196 = (436 + 364) : 4 - 196 = 800 : 4 - 196 = 200 - 196 = 4

б) (867 000 : 2125 – 396) \(\cdot\) 25 = (408 - 396) \(\cdot\) 25 = 12 \(\cdot\) 25 = 300

в) 30 \(\cdot\) 29 – 29 \(\cdot\) 28 + 28 \(\cdot\) 27 – 27 \(\cdot\) 26 = 29(30 - 28) + 27(28 - 26) = 29 \(\cdot\) 2 + 27 \(\cdot\) 2 = 58 + 54 = 112

г) (39² + 39) + (40² – 40) = 39(39 + 1) + 40(40 - 1) = 39 \(\cdot\) 40 + 40 \(\cdot\) 39 = 2 \(\cdot\) 39 \(\cdot\) 40 = 2 \(\cdot\) 1560 = 3120

Ответ: а) 4; б) 300; в) 112; г) 3120