Dãy số trên có số số hạng là:

(149-2):1+1=148(số)

Ghép 2 số liên tiếp từ trái sang phải,ta được 74 cặp,cụ thể:

(149-148)+(147-146)+....+(3-2)

=1+1+1+....+1

Do có 74 cặp mà mỗi cặp có giá trị là 1 nên tổng đó là:74

Vậy tổng của dãy số trên là 74

Chúc em học tốt^^

nếu mik trả lời thì có k cho mik k

Cậu trả lời đi rồi mk k cho  nguyễn phương linh

146. beautifully

147. traditional

148. villagers

149. attraction

150. information

151. activities

152. different

153. pleasure

154. skillful

155. quietness

146. Beautifully

147. Traditional

148. Villagers 

149. Attraction

150. Information

151. Activities

152. Different

153. Pleasure

154. Skilled

155. Quiteness 

ai đổi ko zậy

____________
____________
ik

\(\frac{x+143}{157}+\frac{x+146}{154}=\frac{x+149}{151}+\frac{x+152}{148}\)

\(\Leftrightarrow\frac{x+143}{157}+1+\frac{x+146}{154}+1=\frac{x+149}{151}+1+\frac{x+152}{148}+1\)

\(\Leftrightarrow\frac{x+300}{157}+\frac{x+300}{154}=\frac{x+300}{151}+\frac{x+300}{148}\)

\(\Leftrightarrow\left(x+300\right)\left(\frac{1}{157}+\frac{1}{154}-\frac{1}{151}-\frac{1}{148}\right)=0\)

có \(\frac{1}{157}+\frac{1}{154}+\frac{1}{151}+\frac{1}{148}\ne0\)

\(\Leftrightarrow x+300=0\)

\(\Leftrightarrow x=-300\)

B=150^2-149^2+148^2-147^2+...+2^2-1

=(150-149)(150+149)+(148-147)(148+147)+...+(2-1)(2+1)

=299+295+...+3

số số hạng (299-3):4+1=75

tổng là [(299+3).75]:2=11325

Công thức [a²-(a-1)²]=(a-a+1)(a+a-1)=[a+(a-1)]

có công thức thế vào làm thử ik

Cấu trúc: -ed: cảm xúc của ng (vd: I'm very excited about our trip to Ha Long Bay);

           -ing: miêu tả tính chất, đặc điểm của ng, vật, hiện tg (vd: The trip to Ha Long Bay is very exciting)

146+147. Ted forgets to close his zipper (khóa quần). It is __embarrassing____. Ted feels __embarressed______ (EMBARRASS)

148+149. Michael Phelps is ____excited____. Michael Phelps' Olympic win is ___exciting____. (EXCITE)

150+151. How to get the cheese is ___confusing_____. The mouse is _______confused______. (CONFUSE)

152+153. The taste is ___satisfying_______. I am ___satisfied__.(SATISFY)

154+155. It is an ____exciting______ game. It makes us______excited______.(EXCITE)

156+157. She hears ___surprising____ news. She is so ___surprised___ that she couldn’t say anything. (SURPRISE)

158+159. I have a ______tiring___ job, so my mother always says that I look__tired____at the end of the day. (TIRE)

160+161. Everyone's very ____excited____ about the news because it is such ___ exciting______ news (EXCITE)

162+163. That lamp produces a very ____pleasing___ effect (hiệu ứng), I am very ____pleased____to buy this. (PLEASE)

164+165. I don't like watching __depressing__ films on my own, the actress is always _____depressed___

 (DEPRESS)

166. I am __amazed_____ when she told me she will divorce (ly hôn). (AMAZE)

145. Nam said “I am told to be at school before 7 o’clock”
………………

146. Thu said “All the students will have a meeting next week”
…………

147. Phong said “My parents are very proud of my good marks”
……………………

148. The teacher said “All the homework must be done carefully”
………………

149. Her father said to her “You can go to the movie with your friend”
………………

150. Hoa said “I may visit my parents in the summer”
………………

151. The teacher said “We can collect old book for the poor students”
………………………

không biết 

= (1-2) + ( 3 -4 ) + ..... + ( 145 - 146 ) + 147

= -1 + -1 + .... + -1 + 147

rồi bn tự áp dụng công thức :

\(SSH=\left(\right)SC-SĐ\left(\right):KHOẢNGCÁCH+1\)

Tổng = ( SĐ + SC) X SSH : 2

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