đéo đéo và đéo ok

sao nai nói bn ấy thế , phải văn minh bn ơi

18: \(\left(x^2-4\right)\left(x^2+4\right)=x^4-16\)

19: \(\left(x+y\right)^2+\left(x-y\right)^2=2x^2+2y^2\)

20: \(\left(2x+3\right)^2-\left(x+1\right)^2\)

\(=\left(2x+3-x-1\right)\left(2x+3+x+1\right)\)

\(=\left(x+2\right)\left(3x+4\right)\)

concainit

làm sao

chia ra là 9 chữ rồi còn j

giải luôn nhé 

A= -2x+4y-6z+3x+6y-6-3z

  =x+10y-9z-6

B=4x-6y+8z-4x+12y-4z-5z+5x

  =5x+6y-z

chúc bạn hk giỏi!!!

A = \(-2\left(x-2y+3z\right)-3\left(-x-2y+2\right)-3z\)

A = \(-2x+4y-6z+3x+6y-6-3z\)

A = \(\left(-2x+3x\right)+\left(4y+6y\right)-\left(6z-3z\right)-6\)

A = \(-x+10y-2z-6\)

B = \(2\left(2x-3y+4z\right)-4\left(x-3y+z\right)-5\left(z-x\right)\)

B = \(4x-6y+8z-4x+12y-4z-5z+5x\)

B = \(\left(4x-4x+5x\right)-\left(6y+12y\right)+\left(8z-4z-5z\right)\)

B = \(5x-18y-1z\)

Sắp xếp những từ sau để viết thành câu hoàn chỉnh.

1. badminton/school/classmates/after/play/my/often.

--> My classmates often play badminton after school.

2. school/group/theater/play/they/their/are/a/with/rearsing.

-->They are rearsing a play with their school theater group.

1)My classmates often play badminton after school

2)The are rearsing a play with their school theater group