245/5+(10с+25)/5=162
49+10с+25/5=162
49+5(2с+5)/5=162
49+2с+5=162
54+2с=162
2с=162-54
2с=108
с=54
(1905*690-2006*607+39872):402-284=56
1) 1905*690=1.314.450
2) 2006*607=1.217.642
3) 1.314.450-1.217.642=96808
4) 96808+39872=136680
5) 136680:402=340
6) 340-284=56
106 .....................................................