(2х-3)^2=11х-19
4x^2-12x+9=11x19
4x^2-23x+28=0
D=(-23)^2-4*4*28=81
x1=(-(-23)+9)/2*4=32/8=4
x2=(-(-23)-9)/2*4=14/8=<span>1.75</span>
Cosx/2+cos2x=22 Cos(x\2+2x)/2 *Cos(x\2-2x)/2=2
2 Cos(5x/4) Cos(-3x/4) -2=0
2(Cos(5x/4) Cos(-3x/4)-1)=0
(Cos(5x/4) Cos(-3x/4)-1)=0
Cos(5x/4) Cos(-3x/4=1
Ответ:
(х-8)^3-8=(х-8)(х^2+8х+64)-8