\(x^4-8x=x\left(x^3-8\right)=x\left(x-2\right)\left(x^2+2x+4\right)\)

\(x^2-y^2-6x+9=\left(x^2-6x+9\right)-y^2=\left(x-3\right)^2-y^2=\left(x+y-3\right)\left(x-y-3\right)\)

1 How long do you live in HN

2 How often did you go to the movies

3 What did Mrs Robinson buy

4 When was your father in Nghe An

5 How do they go to school

6 Why didn't she go to class

7 Who left home at 7o'clock yesterday

8 What subject does he study in the high school

9 What is your favorite hobby

10 How far is it

Gọi chiều rộng là x

Chiều dài là 17-x

Theo đề, ta có: \(\left(x+2\right)\left(20-x\right)=x\left(17-x\right)+45\)

\(\Leftrightarrow20x-x^2+40-2x=17x-x^2+45\)

=>18x+40=17x+45

=>x=5

Vậy: Chiều rộng là 5m

Chiều dài là 12m

mình làm phần Iv Writing thui nhá!

1.Do you like play table tennis

2.My friend goes to drama club every tuesday

3.My sister doesnt clean her room everyday