Question

Giải các phương trình sau:

a) 2x(x+2)-3(x+2)=0

b) 5/(x-3)+4(x+3)=x-5/x^2-0

Answer 1

a) 2x(x+2)-3(x+2)=0

\(\Leftrightarrow\)(2x-3)(x+2)=0

\(\Leftrightarrow\)2x-3=0 hoặc x+2=0

\(\Rightarrow\)x\(\in\){-2;\(\dfrac{3}{2}\)}

b) \(\dfrac{5}{x-3}+\dfrac{4}{x+3}=\dfrac{x-5}{x^2-9}\) đk: x\(\ne\)\(\pm\)3

\(\Leftrightarrow\)\(\dfrac{5\left(x+3\right)+4\left(x-3\right)}{x^2-9}=\dfrac{x-5}{x^2-9}\)

\(\Leftrightarrow\)5x+15+4x-12=x-5

\(\Leftrightarrow\)9x+3=x-5

\(\Leftrightarrow\)x=-1