a) \(B=\dfrac{x+1}{x}-\dfrac{x}{1-2x}-\dfrac{3x^2}{2x^2-x}\) \(\left(x\ne0;x\ne\dfrac{1}{2}\right)\)
\(B=\dfrac{x+1}{x}+\dfrac{x}{2x-1}-\dfrac{3x^2}{x\left(2x-1\right)}\)
\(B=\dfrac{\left(x+1\right)\left(2x-1\right)+x^2-3x^2}{x\left(2x-1\right)}\)
\(B=\dfrac{2x^2-x+2x-1+x^2-3x^2}{x\left(2x-1\right)}\)
\(B=\dfrac{x-1}{x\left(2x-1\right)}\)
b) Để B = 0, ta có:
\(\dfrac{x-1}{x\left(2x-1\right)}=0\)
\(\Rightarrow x-1=0\Leftrightarrow x=1\)
Vậy để B = 0 thì \(x=1\)
Đúng 0
Bình luận (0)
