bạn nào giải hộ
vừa biết 1 câu hỏi là acay quá,
cho a+b+c= 30,
chọn a,b,c trong dãy (1,3,5,7,9,11,13,15) điền vào ở trên.
có thể chọn lặp.
K
Khách
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Những câu hỏi liên quan
; a + b - c = - 8 thì :
DT
Đỗ Thanh Hải
CTVVIP
28 tháng 3 2021
1. Nuclear energy is … , but it is dangerous .
A. Renewable B. non-renewable C. natural resource D. fossil fuel
1. fossil fuels are very common in our society but they … the environment .
A. Waste B. pollute C. renew D. provide
2. All the house in our village will be … by solar energy .
A. Frozen B. widened C. heated D. heightened
3. Several governments try to … the use of fossil fuels .
A. waste B. save C. reduce D. increase
4. at this time next week , we … a wind turbine in our garden .
A. will installed B. will be installing C. install D. installed
5. low energy light bulbs should be used to … electricity .
A. convert B. save C. spend D. buy
6. it is a good idea to use … when travelling long distances .
A. private cars B. public transport C. cars D. taxis
7. “why is it called a … source ?” – “ because it can be replaced easily and quickly ”.
A. renewable B. non-renewable C. effective D. specific
8. we must … the amount of water our family use every day .
A. lessen B. narrow C. lower D. reduce
9. wave energy is a source of … energy .
A. environmental friendly B. environmentally friendliness
C. environment friendly D. environmentally friendly
11. alternative sources of energy … developed in the near future .
A. has been B. will be C. is D. was
12. she … cooking in the kitchen at 7 PM tomorrow .
A. will B. is C. will be D. be
13. some new energy-saving bulbs … in the dining room .
A. will be put B. will put be C. will put D. will be putting
14. what should we do to … electricity ?
A. take B. save C. cut D. waste
15. the wind , the sun , and the wave are some types of … sources of energy .
A. cheap B. costly C. changeable D. alternative
DT
Đỗ Thanh Hải
CTVVIP
28 tháng 3 2021
1. Nuclear energy is … , but it is dangerous .
A. Renewable B. non-renewable C. natural resource D. fossil fuel
1. fossil fuels are very common in our society but they … the environment .
A. Waste B. pollute C. renew D. provide
2. All the house in our village will be … by solar energy .
A. Frozen B. widened C. heated D. heightened
3. Several governments try to … the use of fossil fuels .
A. waste B. save C. reduce D. increase
4. at this time next week , we … a wind turbine in our garden .
A. will installed B. will be installing C. install D. installed
5. low energy light bulbs should be used to … electricity .
A. convert B. save C. spend D. buy
6. it is a good idea to use … when travelling long distances .
A. private cars B. public transport C. cars D. taxis
7. “why is it called a … source ?” – “ because it can be replaced easily and quickly ”.
A. renewable B. non-renewable C. effective D. specific
8. we must … the amount of water our family use every day .
A. lessen B. narrow C. lower D. reduce
9. wave energy is a source of … energy .
A. environmental friendly B. environmentally friendliness
C. environment friendly D. environmentally friendly
11. alternative sources of energy … developed in the near future .
A. has been B. will be C. is D. was
12. she … cooking in the kitchen at 7 PM tomorrow .
A. will B. is C. will be D. be
13. some new energy-saving bulbs … in the dining room .
A. will be put B. will put be C. will put D. will be putting
14. what should we do to … electricity ?
A. take B. save C. cut D. waste
15. the wind , the sun , and the wave are some types of … sources of energy .
A. cheap B. costly C. changeable D. alternative
19 tháng 3 2019
Mẹo đó bạn : Ta có : 3!=1x2x3
=>3!+11+13=30.Thỏa mãn bạn nha.
DN
11 tháng 6 2015
không đc đâu 3 số lẻ cộng với nhau sẽ ra số lẻ nên ko thể =30 đc đâu
11 tháng 6 2015
...+...+...=30 nên có ít nhất 1 số chẵn mà trong dãy không có số chẵn nào nên không thể có dãy ...+...+...=30
ta thấy 30 là 1 số chẵn
mà a;b;c chỉ chọn được trong các số lẻ
tổng 3 số lẻ là 1 số le
vậy k tìm được
Mẹo đó bạn : Ta có : 3!=1x2x3
=>3!+11+13=30.Thỏa mãn bạn nha.