x^2-10x+25-10x-x^2=25-20x
при х=-1/20 25-20*(-1/20)=26
(x-5)^2 - x(10+x) = x^2-10x+25-10x-x^2 = 25 -20x =25 - 20*(-1/20) = 25+1=26
x^2-10x+25-10x-x^2=25-20x
при х=-1/20 25-20*(-1/20)=26
(x-5)^2 - x(10+x) = x^2-10x+25-10x-x^2 = 25 -20x =25 - 20*(-1/20) = 25+1=26