Question

[Trần Sơn]

1/(x+2)+5/(2-x)=2x-3/x²-4

giúp mk vs 

Answer 1

[☆Châuuu~~~(๑╹ω╹๑ )☆]

Về học lại hằng đẳng thức nha .-.

\(\Leftrightarrow\dfrac{\left(x+2\right)+5}{2-x}=\dfrac{2x-3}{\left(x-2\right)\left(x+2\right)}\\ \Leftrightarrow-\left(x+2\right)+5\left(x+2\right)=2x-3\\ \Leftrightarrow6x+12-2x+3=0\\ \Leftrightarrow4x+15=0\\ \Leftrightarrow x=\dfrac{-15}{4}\)

Answer 2

[YangSu]

\(\dfrac{1}{x+2}+\dfrac{5}{2-x}=\dfrac{2x-3}{x^2-4}\)

\(\Leftrightarrow\dfrac{1}{x+2}-\dfrac{5}{x-2}-\dfrac{2x-3}{\left(x-2\right)\left(x+2\right)}=0\left(đk:x\ne\pm2\right)\)

\(\Leftrightarrow\dfrac{x-2-5\left(x+2\right)-2x-3}{\left(x-2\right)\left(x+2\right)}=0\)

\(\Leftrightarrow x-2-5x-10-2x-3=0\)

\(\Leftrightarrow-6x-15=0\)

\(\Leftrightarrow-6x=15\)

\(\Leftrightarrow x=-\dfrac{15}{6}\left(n\right)\)

Vậy \(S=\left\{-\dfrac{15}{6}\right\}\)