(cos3x-cosx-sin2x)/(sin3x-sinx+cos2x)=
=(-2sin2xsinx-sin2x)/(2sinxcos2x+cos2x)=
=-sin2x(2sinx+1)/cos2x(2sinx+1)=-tg2x
99sin 1000 / cos 530 = 99*sin(3*360-80) / cos(360+180-10) =
= 99*sin(-80) / cos(180-10) = -99*sin 80 / (-cos 10) =
= 99*sin(90 - 10) / cos 10 = 99*cos 10 / cos 10 = 99
-9х-8+8х-5х+2=-10х
-6х-6+10х=0
4х-6=0
4х=6
х=6/4
х=3/2
х=1,5