-6x(0,5x-1,5)-4,5x-8, при x=2/3
-6*⅔*(0.5*⅔-1.5)-4.5*⅔-8 = = -4*(10/3-15/10)-45/10*⅔ = = -4*(-5)-15/5-8 = = 20-3-8= = 9