-(2-x+x²)+(x²-x-1)-(x²-4x-3) если x=5

-(2-x+x²)+(x²-x-1)-(x²-4x-3)=-2+x-x²+x²-x-1-x²+4x+3=-x²+4x при x=5 -(5)²+4*5=-25+20=-5