Вычислите разумным методом 1)734*100-734*98 2)8300-83*99 3)945*123-745*123+200*887 4) (1281+719):10:25:4 5) 456*79-35*163+544*79-163*65 6)

Вычислим разумным способом:

1) 734 * 100 - 734 * 98 = 734 * (100 - 98) = 734 * 2 = 1468.

2) 8300 - 83 * 99 = 83 * 100 - 83 * 99 = 83 * (100 - 99) = 83 * 1 = 83.

3) 945 * 123 - 745 * 123 + 200 * 887 = 123 * (945 - 745) + 200 * 887 = 123 * 200 + 200 * 887 = 200 * (123 + 887) = 200 * 1010 = 202000.

4) (1281 + 719) :10 : 25 : 4 = 2000 : 1000 = 2.

5) 456 * 79 - 35 * 163 + 544 * 79 - 163 * 65 = 79 * (456 + 544) - 163 * (35 + 65) = 79 * 1000 - 163 * 100 = 100 * (790 - 163) = 100 * 627 = 62700.

6) 456 + 792 - 356 - 792 - 29 = 100 - 29 = 71.

7) (525 - 50) * 2 : ( 373 - 323) = 475 * 2 : 50 = 475 : 25 = 19.

8) 777 * 777 - 777 * 767 - 7670 = 777 * (777 - 767) - 7670 = 777 * 10 - 7670 = 7770 - 7670 = 100.

9) 13095 : 135 * 5 - 10395 : 135 * 5 = 5 * (13095 - 10395) : 135 = 5 * 2700 : 135 = 5 * 20 = 100.