not

Can

Can

He 

She

He is playing football

sings

sings

Cau a : \(A=\frac{a^2\left(a+2\right)-1}{a^2\left(a+2\right)+2a-1}\) => \(A=\frac{-1}{2a-1}\)

Cau b: Neu a la so nguyen thi 2a -1 chac chan phai chia het cho 1 , con tu so la -1 thi da chia het cho 1 roi => day la phan so toi gian

How

Why