Gọi ƯCLN(a; b) là d. Theo đề bài, ta có:

n chia hết cho d => 2n chia hết cho d

2n+5 chia hết cho d

=> 2n+5-2n chia hết cho d

=> 1 chia hết cho d

=> d = 1

=> ƯCLN(a; b) = 1

=> a và b nguyên tố cùng nhau (đpcm)

tick nhé bạn

190 - 120 : 120 -39.25

= 190- 1 - 975

= -786

1. How much fruit ......does...... that farmer ......produce...... every year ?

2. ...Is... he .....going to buy..... a new house next month ?

3. Viet Nam .....has..... a lot of mountains and there .....are..... many tall and big trees there.

I go to a small school but it is very beautiful. My school is in the mountainous village. My school has two floors, it has forty-six teachers and four hundred students . Teachers in my school are very friendly with their students and students in my school are very good. In front of my school has a big yard. We often play sports there. Behind my school , there are many tall trees. To the left of the school, there are many flowers. To the right of the school , there is a well. I love my school very much.

Tui , tui nek, đâu có mak lắp vs chả ráp

What about .....playing..... badminton ?