4 pangkat 1-x+2 pangkat 3-x - 12=0 Selesaikan cepat

^ tanda pangkat
4^1-x + 2^3-x - 12 = 0
4¹ . 4^-x + 2³ . 2^-x - 12 = 0
4 . (2^-x)² + 8 . 2^-x - 12 = 0
misalkan 2^-x = p
4p² + 8p - 12 = 0
(4p - 4)(p + 3) = 0
4p - 4 = 0
4p = 4
p = 1
2^-x = 1
1/^2^x = 1
2^x = 1
2^x = 2^0
x = 0
p + 3 = 0
p = -3
2^-x = -3(tidak ada pangkat hasilnya -)
jadi x = 0