7\20 и 5\12-21\60 и 25\60
11\24 и 1\30-55\120 и 4\120
3\16 и 7\12-9\48 и 28\48
3+4+5=12частей
144:12=12-1 часть
3*12=36-х
4*12=48-у
5*12=60-z
Cos2x + 10cosx - 11 = 0
cos^2 x - sin^2 x + 10 cosx - 11 = 0
cos^2 x - (1 - cos^2 x) <span>+ 10 cosx - 11 = 0
2cos^2 x </span><span>+ 10 cosx - 12 = 0, cos x = t
2t^2 + 10t - 12 = 0
t^2 + 5t - 6 = 0
D = 5^2 + 4*6 = 25 + 24 = 49
t1 = (-5 + 7)/2 = 2/2 = 1
t1 = (-5-7)/2 = -12/2 = -6 - лишний корень
cos x = 1
x = pin, n э Z </span>
201-(176.4:16.8+9.68)*2.5=105.55 176.4:16.8=10.5+9.68=20.18*2.5=50.45
201-50,45= 150.55