Определите значение k , при котором уравнения k + 1 = 2 − 3 x и 2 k + 1 = 2 x − 1 имеют общий корень?

1. proximately twenty years ago children wore strictly school uniform at school. but since the 1990s school uniform has been cancelled. children chose themselves a school dress. anyway, many schools nowadays have school uniform. is it good or had? this question has both advantages and disadvantages.now, let`s consider positive aspects.firstly, the school uniform has strictness which make children study at school more seriously.further more, school uniform makes children more disciplined.more than that it isn`t very expensive. and every family can afford to buy it.more over, school uniform removes social inequality because both rich and poor children wear the same clothes.further more, there is no such a question what to put on in the morning. now, let`s pay our attention, to same negative aspects.school uniform prevents children to be individuality. all are a like. one more, every day one and the same clothes.by the end of the school year it becomes untidy and not pleasant to look at. all in all school uniform has advantages and disadvantages, but as for me personally i vote for the school uniform because i presume it convenient for pupils.извини второе не могу у меня мозг не компьютер

3

Объяснение:

остання цифра добутку (степені числа) залежить лише від добутку останньої цифри кожного з множників

тому  остання цифра числа 987 в степені 987 така ж сама як і остання цифра числа 7 в степені 987

далі 7 =..7 (1 раз множник)

7*7=...9 (2 рази множник)  

7*7*7=..3 ( 3 рази множник)

7*7*7*7=..1 ( 4 рази множник)

7*7*7*7*7=..7 ( 5 раз множник), а значить остання цифра степеней 7 буде повторюватися з періодом 4

987=4*246+3

7 в степені 987=7*7*7**7*7 (987 раз)=

(7*7*7*7) (246 раз) *7*7*7=(...1)(246 раз)*...3=...1*..3=...3

значить остання цифра 3