jika log (2x+5) - log(4x-1) = log 3. nilai x= ....

Kelas 10 Matematika
Bab Logaritma

log (2x + 5) - log (4x - 1) = log 3
log ((2x + 5)/(4x - 1)) = log 3
(2x + 5)/(4x - 1) = 3
2x + 5 = 3 (4x - 1)
2x + 5 = 12x - 3
5 + 3 = 12x - 2x
8 = 10x
x = 8/10
x = 4/5

Syarat
2x + 5 > 0
2x > -5
x > -5/2

4x - 1 > 0
4x > 1
x > 1/4

Maka,
x = 4/5