\(=\sqrt{y-2}-3\cdot8\sqrt{y-2}+4\cdot7\sqrt{y-2}\)
\(=\sqrt{y-2}-24\sqrt{y-2}+28\sqrt{y-2}\)
\(=5\sqrt{y-2}\)
\(\sqrt{y-2}-3\sqrt{64\left(y-2\right)}+4\sqrt{49\left(y-2\right)}\)
\(=\sqrt{y-2}-3\cdot8\sqrt{y-2}+4\cdot7\sqrt{y-2}\)
\(=\sqrt{y-2}-24\sqrt{y-2}+28\sqrt{y-2}\)
\(=\left(1-24+28\right)\sqrt{y-2}\)
\(=5\sqrt{y-2}\)
\(\sqrt{y-2}-3\sqrt{64\left(y-2\right)}+4\sqrt{49\left(y-2\right)}\)
\(=\sqrt{y-2}-3\sqrt{8^2\left(y-2\right)}+4\sqrt{7^2\left(y-2\right)}\)
\(=\sqrt{y-2}-3.8\sqrt{y-2}+4.7\sqrt{y-2}\)
\(=\sqrt{y-2}-24\sqrt{y-2}+28\sqrt{y-2}\)
\(=5\sqrt{y-2}\)
