Sin^2a -cos^2П/3=(4*sin(a)^2-1)/4
2(1-1.5х)+2(х-2)^2=12-3x+2(x²-4x+4)=1
2-3x+2x²-8x+8-1=0
2x²-11x+9=0
D=11²-4*2*9=121-72=49
x1=11-7/4=1
x2=11+7/4=4.5
-3x²+5x-2= -(3x²-5x+2)= -(3·(x-1)(x-2/3)=- (x-1)(3x-2).
D=25-24=1,x1=1,x2=2/3.
2/x = 2x^-1= -1*2x^-1-1 = -2x^-2 = -2/x²