Question

chung to hieu sau day bang mot phan thuc co tu bang 1

\(\dfrac{1}{x}-\dfrac{1}{x+1}\)

Answer 1

\(\dfrac{1}{x}-\dfrac{1}{x+1}=\dfrac{\left(x+1\right)}{x\left(x+1\right)}-\dfrac{x}{x\left(x+1\right)}=\dfrac{x+1-x}{x\left(x+1\right)}=\dfrac{1}{x\left(x+1\right)}\)(đpcm)

Answer 2

\(\dfrac{1}{x}-\dfrac{1}{x+1}=\dfrac{x+1-1}{x\left(x+1\right)}=\dfrac{1}{x+1}\)

\(\Rightarrow\) Đpcm.

Answer 3

\(\dfrac{1}{x}-\dfrac{1}{x+1}\) MTC: \(x\left(x+1\right)\)

\(=\dfrac{x+1}{x\left(x+1\right)}-\dfrac{x}{x\left(x+1\right)}\)

\(=\dfrac{x+1-x}{x\left(x+1\right)}\)

\(=\dfrac{1}{x\left(x+1\right)}\)

\(\Rightarrow dpcm\)