Срочно!! определите х, log5 x=2log5 7-4log5 3

Question

Срочно!!
определите х, log5 x=2log5 7-4log5 3

Answer 1

Log(5) х = 2log(5) 3 + 4*log(25) 7
ОДЗ: x>0
_____2log(5) 3 = log(5) 3^2 = log(5) 9
_____4*log(25) 7 =
= 4*log(5^2) 7 =
= 4*(1\2)*log(5) 7 =
= 2*log(5) 7 =
= log(5) 7^2 =
= log(5) 49
=>
log(5) x = log(5) 9 + log(5) 49
log(5) x = log(5) 9*49
log(5) x = log(5) 441
x = 441