Question

Tìm x, biết: 3/x-5 = -4/x+2

Answer 1

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

\(\Rightarrow3.\left(x+2\right)=\left(x-5\right).\left(x-2\right)\)

\(\Rightarrow3.x+3.2=x.\left(-4\right).-5.\left(-4\right)\)

\(\Rightarrow3x+6=-4x-\left(-20\right)\)

\(\Rightarrow3x=6=-4x+20\)

\(\Rightarrow3x+4x=20-6\)

\(\Rightarrow7x=14\)

\(\Rightarrow x=2\)

Answer 2

\(\dfrac{3}{x-5}=-\dfrac{4}{x+2}\)đk : x khác -2 ; 5 

\(\Rightarrow3x+6=-4x+20\Leftrightarrow7x=14\Leftrightarrow x=2\left(tmđk\right)\)