Question

Rust gọn biểu thức

A= 4(x-3) - 3/x+3/

B=2/x+1/ - /x-1/

Nhanh giúp nha

Answer 1

\(A=4\left(x-3\right)-3\left|x+3\right|\)

- Nếu x > - 3 thì \(A=4x-12-3\left(x+3\right)=4x-12-3x-9=x-3\)

- Nếu x < -3 thì \(A=4x-12-3.\left(-x-3\right)=4x-12+3x+9=7x-3\)

\(B=2\left|x+1\right|-\left|x+1\right|\)

- Nếu x > -1 thì \(B=2\left(x+1\right)-\left(x+1\right)=\left(x+1\right)+\left(x+1\right)-\left(x+1\right)=x+1\)

- Nếu x < 1 thì \(B=2\left(-x-1\right)-\left(-x-1\right)=\left(-x-1\right)+\left(-x-1\right)-\left(-x-1\right)=-x-1\)