7) log(5^2) 5^3 = 3/2 log (5) 5 =3/2
8) log(10) 10 ^1/2 = 1/2 log (10) 10 =1/2
9)15 log (5) 5^2/5 = 15* 2/5 = 3*2=6
10) 2/3 log(2)2^7 = 2/3 * 7=14/3 =4 2/3
11)log(27) log(2) 2^3 = log(27) 3 = log (3^3) 3 = 1/3
12) log(4) log(17) 17^2 - 1/4 log(5) 5^4 =
= log(4) 2 - 1/4 *4 = log(2^2) 2 -1 = 1/2 -1 =-1/2