tìm x biết :(1.2+2.3+3.4+...+2017.2018)/(2018.2019.x)=1/(1+2)+1/(1+2+3)+....+1/(1+2+....+2018)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
I/ Choose the word having the underlined part pronounced differently in each line
1. A. Chairs B. Sofas C. Rooms D. Sinks
2. A. Lamps B. Halls C. Desks D. Lights
3. A. Vases B. Fridges C. Dishes D. Tables
4. A. Houses B. Pictures C. Wardrobes D. Book selves
5. A. Bag B. Family C. Bath D. Fan
II/ Read the conversation below. Underline the final s/es in the words and write /z/ or /s/
Van: Do you live town, Tom?
Tom: Yes, I live in an apartment with my parents.
Van: How many rooms are there in your apartment?
Tom: There are four rooms :a living room, a kitchen, two bedrooms and two toilets.
Van : Is there a supermarket near the apartment?
Tom : Yes, there are also two banks, three restaurants and two hotels.
Van: Are there any shops near it?
Tom: Yes, there are two bookshops, two bakeries and some small convenient shops
III/ Use the words in the box to complete the following passage. Each word is used only once.
This is Nam's room. His room is not very (1)....big......... .There are two (2)....chairs....... , a table. a bed, a wardrobe and an English - Vietnamese (5) ...........dictionary.................. on the table. The wardrobe is (8)....near............... the bed. Nam has many (9) .............clothes......... His clothes are all in the wardrobe. The bookshelf is on the (10).......wall.......... There are many books on it.
The words in the box: [ big; bookshelf; chairs; clothes; dictionary; near; newspapers; opposite; right; wall. ]
I/ Choose the word having the underlined part pronounced differently in each line
1. A. Chairs B. Sofas C. Rooms D. Sinks
2. A. Lamps B. Halls C. Desks D. Lights
3. A. Vases B. Fridges C. Dishes D. Tables
4. A. Houses B. Pictures C. Wardrobes D. Book selves
5. A. Bag B. Family C. Bath D. Fan
II/ Read the conversation below. Underline the final s/es in the words and write /z/ or /s/
Van: Do you live town, Tom?
Tom: Yes, I live in an apartment with my parents.
Van: How many rooms are there in your apartment?
Tom: There are four rooms :a living room, a kitchen, two bedrooms and two toilets.
Van : Is there a supermarket near the apartment?
Tom : Yes, there are also two banks, three restaurants and two hotels.
Van: Are there any shops near it?
Tom: Yes, there are two bookshops, two bakeries and some small convenient shops
III/ Use the words in the box to complete the following passage. Each word is used only once.
This is Nam's room. His room is not very (1)....big......... .There are two (2)....chairs....... , a table. a bed, a wardrobe and an English - Vietnamese (5) ...........dictionary.................. on the table. The wardrobe is (8)....near............... the bed. Nam has many (9) .............clothes......... His clothes are all in the wardrobe. The bookshelf is on the (10).......wall.......... There are many books on it.
The words in the box: [ big; bookshelf; chairs; clothes; dictionary; near; newspapers; opposite; right; wall. ]
Ta có :
\(b^2=\left(3+\sqrt{6+\sqrt{7+\sqrt{2}}}\right)\left(3-\sqrt{6+\sqrt{7+\sqrt{2}}}\right)\)
\(b^2=9-\left(6+\sqrt{7+\sqrt{2}}\right)\)
\(b^2=3-\sqrt{7+\sqrt{2}}\)
\(\Rightarrow b=\sqrt{3-\sqrt{7+\sqrt{2}}}\)
Tích ab :
\(ab=\sqrt{2+\sqrt{2}}.\sqrt{3+\sqrt{7+\sqrt{2}}}.\sqrt{3-\sqrt{7+\sqrt{2}}}\)
\(ab=\sqrt{2+\sqrt{2}}.\left(9-7-\sqrt{2}\right)\)
\(ab=\sqrt{2+\sqrt{2}}.\left(2-\sqrt{2}\right)\)
P/s : làm được thế này thui . Sai bỏ qua
Ta có :
\(x\)và \(x^5\) cùng tính chẵn - lẻ
\(y\)và \(y^3\) cùng tính chẵn - lẻ
\(\left(x+y\right)\)và \(\left(x+y\right)^2\) cùng tính chẵn - lẻ
Vậy \(x^5+y^3-\left(x+y\right)^2\) và \(x+y-\left(x+y\right)\) cùng tính chẵn lẻ
Trong mọi trường hợp, \(x\) và \(y\) lẻ hay chẵn thì kết quả luôn là số chẵn \(\Rightarrow3z^3\) là số chẵn \(\Rightarrow z=2\) ( vì 2 là SNT chẵn duy nhất )
\(\Rightarrow x^5+y^3-\left(x+y\right)^2=3.2^3=24\)
Chỉ khi \(x=y=2\) thì phương trình hợp lí
Vậy \(x=y=z=2\)
vì là nghiệm nguyên nên bạn chỉ cần nhẩm nghiệm xong dùng lược đồ hóc ne là được bạn nhé