Question

Answer 1

b: \(\Leftrightarrow\left(x-2\right)\left(x+2\right)-\left(x-2\right)\left(2x-5\right)=0\)

\(\Leftrightarrow\left(x-2\right)\left(x+2-2x+5\right)=0\)

=>(x-2)(7-x)=0

=>x=2 hoặc x=7

c: \(\Leftrightarrow3\left(3x+2\right)-3x-1=12x+20\)

=>9x+6-3x-1=12x+20

=>3x+5=12x+20

=>x=-5/3

d: \(\Leftrightarrow\dfrac{x\left(x+1\right)}{2\left(x-3\right)\left(x+1\right)}+\dfrac{x\left(x-3\right)}{2\left(x-3\right)\left(x+1\right)}=\dfrac{4x}{2\left(x-3\right)\left(x+1\right)}\)

Suy ra: \(x^2+x+x^2-3x-4x=0\)

\(\Leftrightarrow2x\left(x-3\right)=0\)

=>x=0(nhận) hoặc x=3(loại)