a)Tích của 1 số với 0 thì bằng 0

b)Nếu tích của hai thừa số mà bằng 0 thì có ít nhất một thừa số bằng 0

chúc bạn hok tốt

a ) Tích của 1 số với 0 thì bằng 0

b ) Nếu tích của 2 thừa số mà bằng 0 thì có ít nhất một thừa số bằng 0

a) Tích của 1 số vs 0 thì bằng 0 

b) Nếu tích của hai thừa số mà bằng 0 thì có ít nhất một thừa sô bằng 0

1.      It … the most serious problem .

A. pollution           B. polluted           C. pollute            D. pollutan

1.      It … the most serious problem .

A. pollution           B. polluted           C. pollute            D. pollutant

cảm ơn mọi người ạ 

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

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

cảm ơn ạ 

a) Nếu a<0 thì a+|a|=0

b) Nếu a<0 thì -a>0

a) Nếu a <0 thì -a>0

b) Nếu a<0 thì /a/= -a

c) Nếu a<0 thì a+/-a/=0

P/s: bn ghi dấu gía trị tuyệt đối kiểu j vậy?

VD: a) Giả sử a= -2 thì -a= -(-2)=2>0 (thỏa mãn)

b) Giả sử a= -5 thì /a/=/-5/=5= -(-5)= -a (thỏa mãn)

c) Giả sử a= -10 thì a+/-a/= -10+/-(-10)/= -10+/10/= -10+10=0 (thỏa mãn)

\(M=\left(a+1\right)\left(a+2\right)\left(a+3\right)\left(a+4\right)+1\)

\(=\left(a^2+5a+4\right)\left(a^2+5a+6\right)+1\)

Đặt \(a^2+5a+4=t\)

\(\Rightarrow M=t\left(t+2\right)+1=t^2+2t+1=\left(t+1\right)^2\) là số  chính phương

tớ cũng vậy cứ tưởng là máy tớ bị đơ túc quá đi mất

tại cậu ý cậu thử trở lại trang đầu đi là ních của cậu đă biến mất nguyên nhân chính là máy tích bị lỗi phần mềm