Question

Пожалуйста, помогите решить!

Answer 1

$12)~~8^{2+log_812}=64cdot 8^{log_812}=64cdot 12=768\ \ 13)~~ 9^{log_3 sqrt{5} }=3^{log_35}=5\ \ 14)~~ log_{1/21} sqrt{21} =-log_{21}sqrt{21} =-0.5\ \ 15)~~ (2^{log_27})^{log_73}=7^{log_73}=3\ \ 16)~~ log_a(a^3b^5)=3+5log_ab=3+5cdot frac{1}{log_ba} =3+14=17$

$17)~~ log_a frac{a}{b^9}=1-9log_ab=1-9cdot9=1-81=-80$

Answer 2

12
8²*8^log(8)12=64*12=768
13
3^(2log(3)√5)=3^log(3)5=5
14
log(1/21)√21=-1/2
15
(2^log(2)7)^log(7)3=7^log(7)3=3
16
log(a)a³+log(a)b^5=3log(a)a+5log(a)b=3*1+5*(1:5/14)=3+5*14/5=3+14=17

17
log(a)a-log(a)b^9=1-9log(ab)=1-9*9=1-81=-80

Answer 3

спасибо)