3 pangkat 2x – 5 × 3 pangkat x – 36 = 0

3^2x – 5.3^x – 36 = 0

misal : 3^x = a

a² – 5a – 36 = 0

(a – 9)(a + 4) = 0

a – 9 = 0
a = 9
3^x = 3²
x = 2

a + 4 = 0
a = -4
3^x = -4^0
x = 0