4^x*3*2^x = 2^2x * 3 * 2^x = 3*2^3x
(3*2^3x)^2 - 2*(3*2^3x) - 8 ≤ 0
3*2^3x = z > 0
z² - 2z - 8 ≤ 0
D = 4 + 32 = 36
z12 = (2 +- 6)/2 = 4 -2
(z + 2)(z - 4) ≤ 0
[-2] [4]
z∈ (-∞, -2] U [4, + ∞)
1. z ≥ -2
x ∈ R
2. z ≤ 4
3*2^3x ≤ 4
2^3x ≤ 4/3
3x ≤ log(2) 4/3
x ≤ (log(2) 4/3)/3 = (log(2) 4 - log(2) 3)/3 = (2 - log(2) 3)/3
x ∈ ( -∞. (2 - log(2) 3)/3)
4^x*3*2^x = 2^2x * 3 * 2^x = 3*2^3x
(3*2^3x)^2 - 2*(3*2^3x) - 8 ≤ 0
3*2^3x = z > 0
z² - 2z - 8 ≤ 0
D = 4 + 32 = 36
z12 = (2 +- 6)/2 = 4 -2
(z + 2)(z - 4) ≤ 0
[-2] [4]
z∈ (-∞, -2] U [4, + ∞)
1. z ≥ -2
x ∈ R
2. z ≤ 4
3*2^3x ≤ 4
2^3x ≤ 4/3
3x ≤ log(2) 4/3
x ≤ (log(2) 4/3)/3 = (log(2) 4 - log(2) 3)/3 = (2 - log(2) 3)/3
x ∈ ( -∞. (2 - log(2) 3)/3)