Find the value of $\sqrt{a}\cdot\sqrt{a+6}\cdot\sqrt{b}\cdot\sqrt{b+6}$ for $(a,b)=(7,91)$
Hmmm... it seams that your LaTeX has not loaded correctly. You dont need the dollar signs.
Anyways, I am assuming that you mean \(\sqrt{a}\cdot\sqrt{a+6}\cdot\sqrt{b}\cdot\sqrt{b+6}\), and I also assume that you mean a=7, and b=91, right? From there, all you have to do is plug in 7 for a, and 91 for b. This will give \(\sqrt{7}\cdot\sqrt{13}\cdot\sqrt{91}\cdot\sqrt{97}\) , which is \(\sqrt{803257}\). Sadly, this is not a nice number, but we end up with \(91\sqrt{97}\)