№1. Даны числа: 1724 , 3965 ,7200, 1134. а) Признак делимости на 2 : Если число чётное (заканчивается на 0,2,4,6,8) , то число делится на 2 без остатка. ответ: 1724 , 7200 , 1134. б) Признак делимости на 3: Если сумма цифр числа делится на 3 без остатка , то и всё число делится на 3 без остатка. 1+7+2+4 = 14 ⇒ 14:3 = 4 (ост.2) ⇒ не делится на 3. 3 + 9 +6 +5 = 23 ⇒ 23:3 = 7 (ост.2) ⇒ не делится на 3. 7 + 2 + 0 + 0 = 9 ⇒ 9:3 = 3 ⇒ делится на 3. 1+1+3+4 = 9 ⇒ 9 :3 = 3 ⇒ делится на 3. ответ: 7200 , 1134. в) Признак делимости на 5 : Если последняя цифра числа 0 или 5 ⇒ число делится на 5 без остатка. ответ : 7200 , 3965.
№2. а) 324 ⇒ делится на 2 и 3 [ 3+2+4= 9 ] ⇒ делится на 6 [2*3=6] 438 ⇒ делится на 2 и 3 [ 4+3+8 = 15] ⇒ делится на 6 [2*3=6] Сократим дробь: 324/438 = (324:6) / (438 :6 ) = 54/73
б) 260 ⇒ делится на 2 и 5 ⇒ делится на 10 [2*5=10] 870 ⇒ делится на 2 ,3 и 5 ⇒ делится на 10 [2*5 = 10] 260/870 = 26/87
№4. Каждое число в сумме делится на 3 ⇒ сумма делится на 3 42 +21+ 6 = 3*14 + 3*7 + 3*2 = 3*(14+7+2) = 3*23 ответ: да, можно сделать 3 одинаковых букета по 23 цветка (14 тюльпанов, 7 нарциссов, 2 мимозы).
№5. 18ab / (6a) = (6а * 3b)/6a = 3b/1 = 3b
№6. Было : I склад х т II склад (450-х) т
Стало: I склад (х -75) т II склад (450 - х + 75 ) = (525 - х ) т Зная , что на II складе овощей стало в 2 раза больше , составим уравнение: (525-х) / (х-75) = 2 2(х-75) = 525-х 2х - 150 = 525 - х 2х +х = 525+150 3х= 675 х= 675/3 х= 225 (т) было на I складе 450 - 225 = 225 (т) было на II складе Проверим: (225 +75) / (225-75) = 300/150 = 2 (раза) ответ: по 225 т овощей было на каждом складе первоначально.
If your egg doesn't break the 1st time you can do it again and… Oh, Avenham Park is near the ton of Preston, in Lancashire. May 1st isn't a public holiday in Britain, but the 1st Monday after it is. There are many May Day Celebrations, especially in the country. People erect a maypole then, a tall pole with ribbons hanging from the top. Young children dance round it, holding the ribbons. Teenage girls sometimes enter for the May Queen competition. Halloween is a day on which many children dress up in unusual costumes. The day was originally called All Halloween's Eve, because it fell on October 31, the eve of all Saint's Day. The name was later shortened to Halloween. «Remember, remember the 5th of November» are the words of an old English song. Why? Because in 1605, a man called Guy Fawkes had planned to blow up the Houses of Parliament and kill king James 1st on that day (the king was to open Parliament then). But Guy Fawkes was caught and hanged. And still the British remember Guy Fawkes' Night or Bonfire Night. From early October you can see children with figures (called 'guys') made of sacks and straw and dressed in old clothes. The children say: «Penny for the Guy»- and with the money they collect in this way they buy fireworks. On November 5th the children put their 'Guy' on the bonfire, born it, and light their fireworks…and the British sky is full of light. At the end of the year there are the famous New Year celebrations. In London many people go to Trafalgar Square on New Year's Eve. There is singing and dancing and at 12 o'clock on December 31st - or should we say January 1st? - they all sing the famous song «Auld Lang Syne». A popular Scottish event is the Edinburg Festival for music and drama each year. And perhaps even more known is the Edinburg Military Tattoo from Edinburg Castle early September. A truly Welsh event is the Eisteddfod, a national festival of traditional poetry and music, with a competition for the best new poem in Welsh and for the best choir.
