= > 3s + 1.2.3 + 2.3.3 +....... + 99 . 100 .3

= > 1. 2 .3 + 2.3 ( 4-1 ) + 3.4 ( 5 -2 ) + ... + 99.100. ( 101 -98 )

= > 1 . 2 .3 + 2. 3 .4 - 1. 2 .3 + 3.4.5+- 2 .3 .4 + ...+ 99.100 . 101 - 98 . 100.101

= > 99. 100. 101 = 999900

= > S= 333300

1.số lớn :161

2.số thứ nhất:1414

Ia-3I=0+3

Ia-3I=3

=>a-3=3 hoawcja-3=-3

a-3=3=>a=6

a-3=-3=>a=0

19 nha

Nếu thấy đúng thì tick giùm mình cái nha các bạn

đây là toán lớp 5 đâu phải lớp 7

1. Phuc and mai are studying in the same school T

2. Mai has long black hair and big eyes F

3. She is clever , hard - working , and funny F

4. She likes writing short stories F

5. Phuc and Mai are making a minibook on geography now T

6. They search for information in library books F

7. They are going to the museum to lake photos for their project T

8. After that they will go to the cinema together F

Iam Trang

Da Nang has a population of nearly 800,000 people . the han rivel flows through the city. the city part on the east bank is newew and mor spacious . the city part on the west bank is more crowed . there are five bridges across the river . the han river bridge is the newest one now

the cost of living in da nang is the lowest in central viet nam . da nag has many beaches. among them , non nuoc beach is one of the most beautiful beaches in the wworld. but walking in the street on a summer afternoon is not a good idea in da nang . there are not many trees so there are not many shadows . it is often very hot at noon

quesition

1 what is the population of da nang

-> Da Nang has a population of nearly 800,000 people.

2 which part of the city is more spacious

-> The city part on the east bank

3 which part of the city is more crowed

-> The city part on the west bank

4 which bridge is the newest

-> The han river bridge is the newest

5 What is non nuoc beach like

-> It's one of the most beautiful beaches in the world

Tích nhá

1111.1111.2.2.1 = 4 937 284 

b1 ; 1872 và 92313

b2; 502;55553;6823;641311

b3 ; 102;105;108

b4; 564; 795;2235 

tick ha