Question

Nomor 16 dan 17 pakai cara ya

Answer 1

No.16

²log²(4x-4) - ²log(4x-4)⁴ = ²log⅛
(²log(4x-4))² - 4(²log(4x-4)) = ²log2-³
(²log(4x-4))² - 4(²log(4x-4)) = -3
(²log(4x-4))² - 4(²log(4x-4)) + 3 = 0
misal, ²log(4x-4) = a, maka :
a² - 4a + 3 = 0
(a-1) (a-3) = 0
a=1 v a=3

• untuk a = 1
²log(4x-4) = 1 >> 2¹ = 4x-4
2 = 4x-4
4x = 6
x = 6/4 = 3/2 = 1½
• untuk a = 3
²log(4x-4) = 3 >> 2³ = 4x-4
8 = 4x-4
4x = 12
x = 12/4 = 3
Maka, nilai x adalah B. 3 atau 1½

No.17

Ubah dulu ke bentuk yg sesuai dgn soalnya!
²log3 = x
²log(√3)² = x
2.²log√3 = x
²log√3 = x/2
...
²log25 = y
²log5² = y
2.²log5 = y
²log5 = y/2

Maka , ²log45√3 = ...
= ²log(5×9×√3)
= ²log5 + ²log9 + ²log√3
= ²log5 + 2.²log3 + ²log√3
= y/2 + 2x + x/2
= ½(y + 4x + x )
= ½(y + 5x)
>>>B. ½(5x+y)