Question

Tìm x biết:[(x+1).(2-x)-(x^2-1)]:(x+1)=2

Answer 1

\(\Rightarrow\)\(\left[\left(x+1\right)\times\left(2-x\right)-\left(x^2-1\right)\right]:\left(x+1\right)=2\)

\(\Rightarrow\)\(\left[\left(x+1\right)\times\left(2-x\right)-\left(x-1\right)\times\left(x+1\right)\right]:\left(x+1\right)=2\)

\(\Rightarrow\)\(\left(x+1\right)\times\left(2-x-x+1\right):\left(x+1\right)=2\)

\(\Rightarrow\)\(3-2x=2\)

\(\Rightarrow\)\(2x=1\Rightarrow x=\dfrac{1}{2}\)