Объяснение:
x

Пусть

Тогда

Решаем как обычное квадратное уравнение.

Обратная замена:

Раскладываем по формуле разности квадратов.

Тогда ответ:

Номер 2.

Действуем по той же схеме. Пусть

Так как

То

Снова решаем как обычное квадратное уравнение

Обратная замена.

Тогда ответ:
