a+b+c=(1+3+2):2=3.vậy a=3-3=0;b=1-0=1;c=3-1=2

this is my school . the name of my school is Pho Minh secondary school .It's on Vo Thi Sau street . It's vẻy beautiful and big . there are twevle classroom in my school . my school has two hunred students and thirty teachers . student in my school are very good . they come from around Duc Pho district . our teacher are friendly and kind. at school , Ilearn many suject such as : English , Math ,Art ,... .I like English best because it's very entertaining and importan . at break, I have a lot of activies : skipping ropea , hiding and seeking ,...so on . each day at school is a happy day .I love my school very much .

về trường học

My favorite school is a beautiful school. It is a big and large school. The school has many trees and there has enough stadiums and sporting yards for students to play. The thing I expect the most, that is a great learning school with many modern equipments. One more thing, the students of the school are friendly and helpful and the teachers are good too. That's all of the school in my dream.

con dốc , tick nha , mk trước 

do a+b chia hết cho 7 =>a chia hết 7,b chia hết 7=> a+8b chia hết cho 7

tương tự ở câu b

c thì chứng minh thêm 2009 chia hết cho 7 là được

tick mk nhé

về gia đình

Let me tell you about my family. I live with my mum, my dad and my big sister. We live in Ho Chi Minh city. My mum's name is Linh. She's short and slim, she's got long, black hair and brown eyes. She's a teacher. My dad's name is Nam. He's tall and a little fat! He's got short brown hair and blue eyes. He works in a bank. My sister Huyen is 14 and she loves listening to music. She listens to music all the time! She's got long brown hair and greeen eyes, like me. I've got long hair too. We've got a pet dog, Kiki. He's black and wwhite and very friendly. I love my family very much.