Ответ:

1) 1/(b² — 2 * b + 1) + 1/(b² — 1) = 1/(b — 1)² + 1/((b — 1) * (b + 1));

2) (b — 1)² * (1/(b — 1)² + 1/((b — 1) * (b + 1))) = (b — 1)²/(b — 1)² + (b — 1)²/((b — 1) * (b + 1)) = 1 + ((b — 1) * (b — 1))/((b — 1) * (b + 1)) = 1 + (b — 1)/(b + 1);

3) 1 + (b — 1)/(b + 1) + 2/(b + 1) = 1 + (b — 1 + 2)/(b + 1) = 1 + (b + 1)/(b + 1) = 1 + 1 = 2.

Ответ: 2.