6,9*5*10^-2*10^-3=34,5*10^-2-3=34,5*10^-5=34,5/10^5=345/10^6
Х-любое число.........................
<span>cosx+cos2x+cos3x<0</span>
<span>cos2x+2cos * x+3x/2 * cos* x-3x/2<0</span>
<span>cos2x+2cos2x*cosx<0</span>
<span>cos2x(1+2cosx)<0</span>
<span>cos2x(cos0+2cosx)<0</span>
<span>cos2x * 2cos x/2 * cos x/2 <0</span>
<span>2cosx * cos (квадрат) x/2 <0</span>
все)
X2-6x>0;
x(x-6)>0;
x>0 и x-6>0;
x<6.
Ответ:2