Giúp mjk với!!! >_<
Tập hợp A các số có 4 chữ số khác nhau, chữ số tận cùng là 5. Hỏi có bao nhiêu phần tử trong tập hợp A?
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TL:
= -3/17 - 2/13 - (-20/17) - 11/13
= -3/17 + 20/17 - ( 2/13 + 11/13)
= 1 - 1 = 0
_HT_
Bạn tham khảo nhé!!!
Bài 1:
I live in a house at ____(Bạn tự điền tên đường vào nhé!) street with my family. My house is small but it is very beautiful. It has 3 bed room, one for my parent, one for my sister ( hoặc là brother, tùy bạn chọn thôi) and one for me. The living room is small but it is very nice and the kitchen is very convenient. My house also has a small garden with some trees and flowers that my father is planted. My house isn't large but it very beautiful, and I enjoy it very much.
Bài 2:
This is my house. My house has 7 rooms which are the living room, my parent’s the bedroom, my the room, the kitchen, the dining room, the bathroom and the toilet.In the livingroom , you will see the altars the first. It is put in high position highly. In the mid-room ,table and chair are put in here there are chairs and tables .(not sofa, not armchair). We have some pictures on the above wall. The TV is put behind the table and the chairs .In my the room, the computer is put beside the desk and the bookshelf is put next to the desk. On the left, the bed is put near the wardrobe.In the kitchen, the cupboard is put near the refrigerator and the stove and the cooking rice.
Câu 21:
1: \(\Leftrightarrow5\sqrt{x-1}=10\)
=>căn x-1=2
=>x-1=4
=>x=5
2: Để hai đường song song thì -2m=3m-5
=>-5m=-5
=>m=1
\(=\dfrac{x+2+x-\sqrt{x}-x-\sqrt{x}-1}{\left(\sqrt{x}-1\right)\left(x+\sqrt{x}+1\right)}\cdot\dfrac{2}{\sqrt{x}-1}\)
\(=\dfrac{2}{x+\sqrt{x}+1}\)
Số các số hạng là:
(30-20):1+1=11 (số)
Tổng là:
(30+20)x11:2=275
Đáp số:275