Пошаговое объяснение:
1. пусть числа будут (х-2) (х-1) х (х+1) (х+2) х>2
∨ знак сравнения
(х-2)² + (х-1)² + х² ∨ (х+1)² + (х+2)²
х²- 4х + 4 + х² - 2х + 1 + х² ∨ х² + 2х + 1 + х² + 4х + 4
x² - 12x ∨ 0
x(x-12) ∨ 0 x>2
[0] [2] [12]
при x>2 до 12
то есть от чисел 1 2 3 4 5 до 9 10 11 12 13 cумма трех первых меньше 2-х последних
при 10 11 12 13 14 сумма 10²+11²+12² = 13² + 14²
при больших 11 12 13 14 15 сумма трех первых будет больше 2-х последних
2. 4+5=9
4*5=20
20-9=11
ответ:4
Russia is one of the largest countries in the world. The vast territory of Russia lies in the eastern part of Europe and the northern part of Asia.
Russia is washed by 12 seas and three oceans. It borders on many countries, such as Mongolia and China in the south-east, Finland and Norway in the north –west and so on.
The land of Russia varies very much from forests to deserts, from high mountains to deep valleys. The main mountain chains are the Urals, the Caucasus and the Altai.
There are a lot of great rivers and deep lakes on its territory. The longest rivers are the Volga, the Lena and the Yenisei.
Baikal is the deepest lake in the world and its water is the purest in the world.
The current population of Russia is more than 150 million people.
The capital of Russia is Moscow with the population of about 110 million people.
Russia is a presidential republic. It has also its own Parliament, which consists of two chambers.
