Ta có

\(xA=x^{12}+x^{11}+....+x\)

\(\Rightarrow xA-A=\left(x-1\right)A=\left(x^{12}+....+x\right)-\left(x^{11}+1\right)=x^{12}-1\)

Giải tương tự ta được \(\left(x-1\right)B=x^6-1\)

Ta có

\(A:B=\left(x-1\right)A:\left(x-1\right)B=\frac{x^{12}-1}{x^6-1}\)

Kẻ Bz//Cy

Ta có

\(\widehat{C1}=\widehat{B1}=20^0\)( Hai góc so le trong )

Mặt khác

\(\widehat{B1}+\widehat{B2}=85^0\)

\(\Rightarrow\widehat{B2}=85^0-20^0=65^0\)

\(\Rightarrow\widehat{B2}+\widehat{A1}=115^0+65^0=180^0\)

Mà \(\widehat{B2};\widehat{A1}\) là 2 góc trong cùng phía

=> Bz//Ax

=> Ax//Cy

hic

hum qua kiếm dc có 3 GP

khác nhau ở cái tên

Mặc kệ nó

Làm tri kỉ vs 1 đứa khác

1.  My father is is a doctor

2 .  He goes to work by bus

3  My mother is a teacher

4 She teaches English at a school near my house

5 . My brother is a student 

6 .  He studies at a university in England

7 My cousin is a baby

8 . He sleeps all day

9 .My grandmother is a housewife

10  She is a good cooker

11  My neighbor is a hair dresser

12 .She ís kind and friendly