We have to evaluate the expression:
[tex]3a-\sqrt{a^2+b^2}[/tex]where a = -6 and b = 8.
To do that we replace a and b with the corresponding values and then calculate the expression:
[tex]\begin{gathered} 3(-6)-\sqrt{(-6)^2+8^2} \\ -18-\sqrt{36+64} \\ -18-\sqrt{100} \\ -18-10 \\ -28 \end{gathered}[/tex]Answer: -28
