Carilah HP untuk setiap persamaan logaritma berikut.
2.
2x + 3log (x2 - 3x + 2) = 2x + 3log (5x - 10)
Jawaban :
2x + 3log (x2 - 3x + 2) = 2x + 3log (5x - 10)
x2 - 3x + 2 = 5x - 10
x2 - 3x - 5x+ 2 + 10 = 0
x2 - 8x + 12 = 0
(x - 6)(x - 2) = 0
x = 6
atau
x = 2
cek dulu,
jika x = 6
2x + 3
= 2 .6 + 3
= 12 + 3
= 15 > 0
maka x = 6 termasuk HP
jika x = 2
2x + 3
= 2 . 2 + 3
= 4 + 3
= 7 > 0
maka x = 2 juga termasuk HP
HP : x = 2 dan x = 6
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