6. а) √3 * √27 = √3* 27= √81 = 9
б) ( - √2) * √32 = - √ 2 * 32 = - √64 = - 8
7. а) √24 : √6 = √24 : 6 = √4 = 2
б) ( - √343) : √ 7 = - √343 : 7 = - √49 = - 7
8. а) 2.5^ 8 * 2.5 ^ 4 = 2.5^ 12
б) 7.1^ 9 : 7.1^ 6 = 7.1 ^ 3
г) (√7)^ 3 * 3√7 = 3√7 ^ 4
д) 4.2^ 5 * 0.5^ 5= (4.2 * 0.5)^ 5 = 2.1^ 5