\(\frac{3x+3}{4x+5}=\frac{6x+2}{8x+4}\)
\(\Leftrightarrow(3x+3)(8x+2)=(4x+5)(6x+2)\)
\(\Leftrightarrow24x^2+6x+24x+6=24x^2+8x+30x+10\)
\(\Leftrightarrow24x^2+30x+6=24x^2+30x+8x+10\)
\(\Leftrightarrow6-10=8x\)
\(\Leftrightarrow-4=8x\)
\(\Leftrightarrow-\frac{1}{2}=x\)
vậy \(x=-\frac{1}{2}\inℝ\)