The expression is given to be:
[tex]\frac{a^2-36}{5a+30}[/tex]
From the numerator, using the difference of two squares, we have:
[tex]a^2-36=a^2-6^2=(a-6)(a+6)[/tex]
From the denominator, by factorization, we have:
[tex]5a+30=5(a+6)[/tex]
Therefore, the expression becomes:
[tex]\Rightarrow\frac{(a-6)(a+6)}{5(a+6)}[/tex]
Cancel out common terms in the denominator and numerator. The simplified expression will be:
[tex]\Rightarrow\frac{a-6}{5}[/tex]
From the original expression, the variable restriction will be at:
[tex]\begin{gathered} 5a+30=0 \\ Solving \\ 5a=-30 \\ a=-\frac{30}{5} \\ a=-6 \end{gathered}[/tex]
The restriction is:
[tex]-6[/tex]