Question

11$x^{2}$ - 891 = 0;

Answer 1

11х²-891=0,
11х²=891,
х²=81,
х=±9,
х=-9,
х=9.
Ответ: -9; 9.

Answer 2

11х^2=891
  x^2=891/11
  x^2=81
   x1=-9
   x2=9
 Ответ:-9; 9