Question

log21 3*log21 147+log21 7решение какое

Answer 1

$log_{21} 3 * log_{21}147+log_{21}7=log_{21}3*(log_{21}21+log_{21}7)+log_{21}7=$
$log_{21}3*(1+log_{21}7)+log_{21}7=log_{21}3+log_{21}3*log_{21}7+log_{21}7=$
$log_{21}3+log_{21}7+log_{21}3*log_{21}7=1+log_{21}3*log_{21}7$
А дальше вроде никак не упростишь.....