\(\left(y+1\right)+\left(y+4\right)+\left(y+7\right)+...+\left(y+31\right)+\left(y+34\right)=222\\ \Leftrightarrow\left(y+y+y+...+y\right)+\left(1+4+7+...+31+34\right)=222\\ \Leftrightarrow12y+210=222\\ \Leftrightarrow12y=222-210=12\\ \Rightarrow y=\dfrac{12}{12}=1\)

* Số các số hạng y là: \(\left(34-1\right):3+1=12\)

* Tổng dãy số từ 1 - 34 là: \(\dfrac{\left(34+1\right).12}{2}\) = 210 ( số )

a, A = { x \(\in N\), x là số lẻ và x<10 }

b, B = { x \(\in N\), x chia hết cho 3 và 0<x<20}

c, C = { x \(\in N\), các số tự nhiên cách nhau 4 đơn vị và 1<x<23}

d, D = { x \(\in N\), \(2^x\) và \(x\le6\)}

1 The lights weren't left on

2 weren't called

3 was chased by the dog

4 were answered by Gwen

5 was left on the desk by Tim

6 has offered job

7 will be directed by the MC

8 laptop was given to me

9 was laughed by all his friends

10 was destroyed by the flood

11 line must not be crossed

12 apartment is bought by my parents

1 traveling around

2 small village

3 old church

4 raking the grass

5 cemetery

6 die

7 carefully

8 die once

9 correctly

10 All of them

1 reads

2 play

3 swim 

4 is sleeping

5 likes

6 watch

7 sing

8 cooks

9 arrives

10 brushes

Chọn A. thing /θ/

Các đáp án B.father và C.there đều phát âm /ð/

Tổ quốc