-
Вопрос по алгебре:
Докажите что уравнение x^2-y^2=30 не имеет решения в целых числах.
-
Автор:
amyalvarez
-
-
Ответ:
x^2-y^2=30
(x-y)(x+y)=30
так как x,y- целые, то x-y и x+yтоже целые
30=1*30=(-1)*(-30)=2*15=(-2)*(-15)=(-3)*(-10)=3*10
решив 12 систем
x-y=1
x+y=30
x-y=30
x+y=1
x-y=-1
x+y=-30
x-y=-30
x+y=-1
и т.д. легко убедиться что целых решений на одна их систем не имеет, а значит и данное уравнение не разрешимо в целых числах, т.е. не имеет решения в целых числах
-
Вопрос по алгебре:
найдите седьмой и знаменатель геометрической прогрессии с положительными членами, если b6=28, b8=7-
Ответов: 1
-
-
Вопрос по алгебре:
На рисунке изображён график функции y f x заданной на промежутке [ -6 6
]найдите промежуток не содержащий ни одного решения неравенства >0-
Ответов: 2
-
-
Вопрос по английскому языку:
Помогите перевести текст: Animals of India. Начинается The Begal tiger national animal of India.................-
Ответов: 2
-
-
Вопрос по английскому языку:
1.
Nowadays solar energy is widely used as an alternative form of power. Solar panels transform the energy from the sun into electricity. The first plane that does not need fuel was constructed in France, in 2015. It uses only the sun's energy. The panels are placed on the huge wings of the plane. It doesn’t fly very fast. Solar energy can make the plane move at only 140 miles an hour. However, the plane is able to travel round the world. It is safe and can successfully cross areas of bad weather. In the future, engineers hope to construct a model that people can fly in. Our dream of environmentally friendly transport may come true very soon. Would you like to take a flight on the solar plane?
Do you know why it is hot in the summer and cold in the winter? Most people believe that it is because the Earth is closer to the Sun in the summer and farther from it in the winter. But it is not like this at all! In fact, the distance between the Earth and the Sun is largest in July and smallest in January! Scientists suggest that the reason for different summer and winter temperatures is the angle of the Sun’s rays. In the summer, the rays reach the Earth almost at a right angle. Due to this, the rays are not spread out and a smaller area of the planet's surface gets the energy. In the winter, the angle changes and the Sun’s rays are spread out over a larger area. Besides this, the long nights and short days do not give enough time for the land to warm up.
Нужно написать по русски текст, как читается(зе атик оушен из зе смоулест оушен оф зе велд)-
Ответов: 1
-