Log(4x+5) по основанию 5 =2+log(x-4) по основаю 5

Log(4x+5) = 2 + log(x-4) => log(4x + 5) - log(x - 4) = 2
=> log((4x + 5) / (x - 4)) = 2
=> (4x + 5) / (x - 4) = 25
=> 4x + 5 = 25x - 100
=> 21x = 105
=> x = 5