Tìm x biết : 

a ) 2^x +2^x+4 = 544

b ) 4^2x+1 + 4^2x = 80 

c ) 3^2x+2+3^2x+1 = 108

d ) 7^x+3-7^x+1 = 16464

Cộng các tích tìm được: 4xy bình + 6xy bình - 2x mũ 3 y mũ 2 = bao nhiêu

thay đổi câu thành câu chủ động

1. more in rormation was given to us by her

-...........

2. All the workers of the plan were being instructed by the chief engineer 

- ........

3. tea cannot be made with cold water by them 

-......

4. the engine of the car has to be repaired 

-.....

5. we were given two exercise books by the teacher

-..........
 

Tìm x : 5^x+1-5^x = 20

thay đổi thành câu chủ động

1. The woman with the red hat is looked at by the children 

-...........

2. Are inquires about the thief bring made by the police ?

- .......

3. must this machine be used before 5 :30 p.m by us ?

-.....

4. by whom will the childen be looked after by ?

- ........

5. how much are you paid  to do the job by them ?

- .........