start expanding the squared expression using the square of a binomial,
[tex](a+b)^2=a^2+2\ast a\ast b+b^2[/tex]then,
[tex]\begin{gathered} (x+5)^2=x^2+2\ast5\ast x+5^2 \\ (x+5)^2=x^2+10x+25 \end{gathered}[/tex]replace in the original function
[tex]-5(x^2+10x+25)-2[/tex]apply distributive and simplify
[tex]\begin{gathered} -5x^2-50x-125-2 \\ -5x^2-50x-127 \end{gathered}[/tex]Answer:
[tex]-5x^2-50x-127[/tex]