Answer:
Step-by-step explanation:
81 = 9 * 9 = 3 * 3 * 3 *3
8 = 2 * 2 * 2 *2
[tex]\sqrt{81 * 8 } = \sqrt{3*3*3*3*2*2*2}\\\\=3 * 3 * 2 \sqrt{2}\\\\= 18\sqrt{2}[/tex]
