<span>(x+5)</span>²<span> + (x-2)</span>²<span> + (х-7)(x+7) = 11x+30
х</span>²+10х+25 + х² - 4х+4 + х²-49 = 11х+30
3х²-5х-50 = 0
D = 35-600
D<0
Уравнение не имеет решения
(x-6)x(x^2+6x+36)=x^3-6^3=x^3-216
(x-y)²-(x-y)(x+y)=x²-2xy+y²-(x²-y²)=
x²-2xy+y²-x²+y²=2y²-2xy