4題LOG數

(34) y = log(2√3)144
y = log144 / log(2√3)
y = log(12^2) / log (√12)
y = 2log12 / [0.5log(12)]
y = 4
(35) 4^x = 20 - 4^(x + 1)
4^x = 20 - (4)(4^x)
(5)(4^x) = 20
4^x = 4
x = 1
(36) 3^(x + 2) - 3^(x + 1) = 18
(9)(3^x) - 3(3^x) = 18
(6)(3^x) = 18
3^x = 3
x = 1
(37) 3^x = 4^(x - 1)
x log3 = (x - 1)log4
x log3 = x log4 - log4
(log4 - log3)x = log4
x = log4 / (log4 - log3) = 4.82