[tex]8 \sqrt{75}-5 \sqrt{48}= \\
=8 \sqrt{25 \times 3}-5 \sqrt{16 \times 3}= \\
=8 \times 5\sqrt{3}-5 \times 4 \sqrt{3}= \\
=40\sqrt{3}-20 \sqrt{3}= 20 \sqrt{3} \\
20 \sqrt{3}+ 8,5\% \times 20 \sqrt{3} = 20 \sqrt{3} \times 1,085 = \boxed{21,7 \times \sqrt{3}}[/tex]
