· Tên: Tokuda Satoru

· Lớp: 7->8

· Link của nick: ấn vô avatar

4) I think he has donated (donate) blood several times before

5) The children haven't finished (not/fisish ) painting the mural over

6) we haven't completed (not/complete) cleaning up the streets yet

-He didn't send a letter to hí penpal last week.

1.

gọi UCLN(n+1;3n+4) là d

ta có :

n+1 chia hết cho d=>3(n+1) chia hết cho d =>3n+3 chia hết cho d

=>3n+4 chia hết cho d

=>(3n+4)-(3n+3) chia hết cho d

=>1 chia hết cho d

=>d=1

=>UCLN(n+1;3n+4)=1

=>n+1;3n+4 là hai số nguyên tố cùng nhau

1. I can't stand the unpleasant ( please) smell of bad fish.

2. The scouts also help the elders ( old) and street children.

3.Will you please give me some further ( far) explanation.

4.The circus performed ( perform) by David was very successful.

5. Use public transport or we won't minimize ( minimum) pollution.

6. He's a very well-known film producer ( produce).

7.He's an experienced ( experience) doctor who just graduated from the medical school last year.

8. Two of the biggest problems facing any society are unemployment ( employ) and crime.

9.He had been nominated as the most effective activist ( active) in the town charity program.

10.We think that Mother's day should be celebrated nationally ( nation).

182 hs nhé.

a, A= \(5\left(\dfrac{1}{1.2}+\dfrac{1}{2.3}+...+\dfrac{1}{99.100}\right)\)

\(A=5\left(1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+...+\dfrac{1}{99}-\dfrac{1}{100}\right)\)

\(A=5\left(1-\dfrac{1}{100}\right)\)

\(A=5.\dfrac{99}{100}=\dfrac{99}{20}.\)

b, \(C=1.2.3+2.3.4+...+8.9.10\)

\(4C=1.2.3.4+2.3.4.\left(5-1\right)+...+8.9.10.\left(11-7\right)\)\(4C=1.2.3.4+2.3.4.5-1.2.3.4+...+8.9.10.11-7.8.9.10\)\(4C=8.9.10.11\)

\(C=\dfrac{8.9.10.11}{4}=1980.\)

c, https://hoc24.vn/hoi-dap/question/384591.html

Câu này bạn vào đây mình đã giải câu tương tự nhé.

1. He and I are in class 7A ( Viết lại với too)

=>He is in class 7A and I am, too.

2. Since they didn't have enough money, they couldn't buy that house ( There fore)

=> They didn't have enough money, therefore, they couldn't buy that house