(x^2 + 1)/(x - 3) - 10/(x - 3) = (x^2 + 1 - 10)/(x - 3) = (x^2 - 9)/(x - 3) = (x - 3)(x + 3)/(x - 3) = x + 3;
При x = 57;
57 + 3 = 60.
(x^2 + 1)/(x - 3) - 10/(x - 3) = (x^2 + 1 - 10)/(x - 3) = (x^2 - 9)/(x - 3) = (x - 3)(x + 3)/(x - 3) = x + 3;
При x = 57;
57 + 3 = 60.