Question

Aratati ca log₅245= 2a +1 ,unde a= log₅ 7.

Answer 1

log5 245=3,4
log5 7=1,2
3,4=2×1,2+1
3,4=2,4+1
3,4=3,4
3,4+3,4=6,8

Answer 2

$245 = 5 * 7^2$ => $log_5 245 = log_5(5*7^2) = log_5 5 + log_5 7^2 = 1 +log_5 7^2$

$a=log_5 7$
1 + $log_5 7^2 = 1+log_57+log_57 =\ \textgreater \ 2a+1$