[tex]\begin{gathered} f(c)=\frac{f(5)-f(-1)}{5-(-1)}=\frac{31-7}{6}=\frac{24}{6}=4 \\ \text{therefore we have to solve } \\ 2x^2-4x+1=4 \\ 2x^2-4x-3=0 \end{gathered}[/tex]
can you see this? The MVT need a closed interval, so you can't apply it. Even if you could do it, the solution to the last polynomial are not integers, so the option you have it
