Penyelesaian 2 log (x-2) + 2 log (x+5) = 3 adalah..

Kelas 10 Matematika
Bab Logaritma

^ = pangkat

²log (x - 2) + ²log (x + 5) = 3
²log ((x - 2) (x + 5)) = 3
x² + 3x - 10 = 2^3
x² + 3x - 10 - 8 = 0
x² + 3x - 18 = 0
(x + 6) (x - 3) = 0
x + 6 = 0
x = -6

x - 3 = 0
x = 3

Syarat
x - 2 > 0
x > 2

x + 5 > 0
x > -5

Maka
x = 3

=²log (x - 2) + ²log (x + 5) = 3
=²log ((x - 2) (x + 5)) = 3
=x² + 3x - 10 = 2^3
=x² + 3x - 10 - 8 = 0
=x² + 3x - 18 = 0
=(x + 6) (x - 3) = 0
=x + 6 = 0                 = x-3=0
=x = -6                      = x=3