=40 

tick nhé bạn

dễ mà,bạn nên tự suy nghĩ để làm

thế đừng nói 

1. I have a best friend. Her name's Diệu Linh. Her age is twelve so she is in grade six and she is a good student.She has got a long, black and straight hair. Linh's eye is black , her eye very nice ! ....v .v ( bạn tự tả tiếp ) I hope Linh and I will is good friend forever !

1. That room of mine is not very large, just small and pretty. The room was on the second floor, next to my dad's office and next to the stairs. The wall of the room is completely painted in pink and white. Two colors that I love very much. And those two colors make my room brighter and lighter, more beautiful. There is a window in the room. From that window, I can see the backyard of my house. Every morning, when opening the window, the sunshine will flood into the room, making the small room bright. Every afternoon, the orphan wind will come from outside, through the sliding window into the room, so my room is still very cool even though it's summer. In winter, when the door is closed, it is extremely warm. Next to the window is my desk. A wooden study table designed by my father himself. The beautiful little table is where I study. Opposite the desk is the bed. Next to the bed is my bookshelf. In the room, the bookshelf is my favorite thing. That's where I neatly put the books of fairy tales, literature, history... that I love the most. After every stressful lesson, I choose a book for myself and go to bed to relax.
2.
In the living room, there is a set of ironwood tables and chairs, delicately carved. There is always a lovely flower vase on the table, taken care of by her mother. In front is a large wooden cabinet, put vases, books, or small souvenirs. In the center of the cabinet is a large television that my father bought last year. To the right is a large window, overlooking the main street. Every weekend, my whole family will sit here watching movies, having fun chatting. The kitchen was a place that was often jokingly said to be Mom's private territory. There is a large refrigerator, a set of tables and chairs, and cabinets and shelves for kitchen tools. They are neatly arranged by their mother according to their own rules. A lot of items but mom always remembers where they are. That's very wonderful.

a=-8

b=20

c=-7

tick nhé

n vừa chia hết cho 2 vừa chia hết cho 7; mà ( 2 ;7 ) =1 nên n chia hết cho 14.

Tập hợp đó là:

{112 ; 126 }

gọi UCLN(2n+1;6n+5) là d

=>2n+1 chia hết cho d

=>3(2n+1) chia hết cho d

=>6n+3 chia hết cho d

=>6n+5 chia hết cho d

=>(6n+5)-(6n+3) chia hết cho d

=>2 chia hết cho d

=>d E U(2)={1;2}

nếu d=2

=>2n+1 là số lẻ không chia hết cho 2

=>d=1

=>UCLN(2n+1;6n+5)=1