Theo hệ thức vi ét ta có : \(\hept{\begin{cases}x_1+x_2=\frac{-b}{a}=\frac{2m+4}{1}\\x_1x_2=\frac{2m+3}{1}\end{cases}}\)
\(\left(4x_1+1\right)\left(4x_2+1\right)=25\)
\(< =>16x_1x_2+4x_1+4x_2+1=25\)
\(< =>16\frac{2m+3}{1}+4\frac{2m+4}{1}=24\)
\(< =>32m+48+8m+16=24\)
\(< =>40m=24-64=-40\)
\(< =>m=-1\)