ada yg tau jawabannya?

jawab
(1)
2²ˣ⁻¹  - 1 = 2ˣ⁻¹
2²ˣ⁻¹ - 2ˣ⁻¹ - 1 = 0
2[2²ˣ⁻¹ - 2ˣ⁻¹ - 1 ] = 2(0)
2²ˣ⁻¹⁺¹ - 2ˣ⁻¹⁺¹ - 2 = 0
 2²ˣ - 2ˣ - 2 = 0
2ˣ = a → x = ²log a  , a > 0

a² - 2a - 2= 0
(a - 2)(a + 1)= 0
a = 2 atau a = - 1 (tidak memenuhi )

a= 2 → x= ²log 2 = 1

(2)
²⁰log 3 = p → ³log 20 = 1/p
⁵log 3 = q → ³log 5 = 1/q
³log 100 = ³log 20 + ³log 5 = 1/p + 1/q = (p+q)/)pq)

(3)
2²⁻²ˣ +2 - 9/(2ˣ)  > 0 ..."kalikan 2ˣ
2ˣ { 2²⁻²ˣ  +2 - 9/(2ˣ)} > 0
2².2⁻²ˣ⁺ˣ + 2.2ˣ - 9  > 0 
4.2⁻ˣ.+ 2. 2ˣ - 9 >0

2ˣ = a → x= ²log a , a > 0
4/a  + 2a - 9 > 0 } kali a
2a² - 9a  + 4 > 0
(2a -4)(a-1) >0
a > 2  atau a <  1

a >2 → 2ˣ > 2¹ 
x  > 1

a < 1 → 2ˣ < 2⁰
x < 0

HP  x < 0 , x > 1

(4)
2⁻ˣ^² ⁺ˣ⁶ = {ᵃlogb. c'log a}/(c'log b)
2⁻ˣ²⁺ˣ⁺⁶ = {b'log c. c'log a. a'log b}
2⁻ˣ^²+x+6 = b'log b = 1 = 2⁰

-x² + x + 6 = 0
x² - x  - 6  = 0
(x - 3)(x+2)=0
x = 3  atau x = - 2