Question

(x-9)^2=2х(х-9)-19
Пожалуйста, решите подробно

Answer 1

$\displaystyle\bf\\(x-9)^{2} =2x(x-9)-19\\\\x^{2} -18x+81=2x^{2} -18x-19\\\\x^{2} -18x-2x^{2} +18x=-19-81\\\\-x^{2} =-100\\\\x^{2} =100\\\\x_{1,2} =\pm \ \sqrt{100} =\pm \ 10\\\\x_{1} =-10 \ \ : \ \ x_{2} =10\\\\Otvet: \ -10 \ \ ; \ \ 10$