Question

-(2-x+x²)+(x²-x-1)-(x²-4x-3)
если x=5

Answer 1

-(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