Question

Nilai x yang memenuhi persamaan :
.

adalah.............

Answer 1

3^2x - 5 . 3^x - 36 = 0
(3^x)^2 - 5 . 3^x - 36 = 0
Misal 3^x = a
a^2 - 5a - 36 = 0
(a - 9)(a + 4) = 0
a = 9 atau a = -4
1) a = 9 => 3^x = 3^2 => x = 2
2) a = -4 => 3^x = 3^... => Tidak ada nilai x yang memenuhi
Jadi x = 2