2y^2 - 3y+2y - 2y^2 = -3y+2y= -y
1)3/х+3 + 3/х2-3х + 2х/9-х2=3/х+3 + 3/х(х-3) + 2х/(3-х)(3+х)=3•(х(х-3) + 3•(х+3) -2х•х/х(х+3)(х-3)= 3х2-9х+3х+9-2х2/х(х-3)(х+3)=х2-6х+9/х(х-3)(х+3)=(х-3)2/х(х-3)(х+3)=х-3/х2+3х
3)а^2-b/a-a=0,04+25-0,2=24,84
SABC=1/2 AB*CK=1/2*18*12=108 SABC=1/2 AC*BH=1/2*27*BH 1/2 *27*BH=108 BH=108*2/27=8
Формулы:
sin (a+в)=sin a*cos в + sin в*cos a;
sin (a-в)=sin a*cos в - sin в*cos a;