Please help me solve this
Thanks!
Thanks!
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Lets give 5^x a value of y:
y^2 - 6y + 5 = 0
Factor it out:
(y - 5) (y - 1) = 0
Solve for each:
y - 5 = 0
y = 5
y - 1 = 0
y = 1
Now substitute 5^x back for y and solve for each:
5^x = 5
x = 1
5^x = 1
x = 0
--------------
Overall:
x = 0, 1
y^2 - 6y + 5 = 0
Factor it out:
(y - 5) (y - 1) = 0
Solve for each:
y - 5 = 0
y = 5
y - 1 = 0
y = 1
Now substitute 5^x back for y and solve for each:
5^x = 5
x = 1
5^x = 1
x = 0
--------------
Overall:
x = 0, 1
-
5^(2x) - [6 * 5^(x)] + 5 = 0 → you know that: x^(ab) = x^(ba)
5^(x * 2) - [6 * 5^(x)] + 5 = 0 → you know that: x^(a * b) = (x^a)^b
[5^(x)]² - 6 * 5^(x) + 5 = 0 → let: X = 5^x → where X > 0 of course
X² - 6X + 5 = 0
Polynomial like: ax² + bx + c, where:
a = 1
b = - 6
c = 5
Δ = b² - 4ac (discriminant)
Δ = (- 6)² - 4(1 * 5) = 36 - 20 = 16 = 4²
X1 = (- b - √Δ) / 2a = (6 - 4) / (2 * 1) = 1
X2 = (- b + √Δ) / 2a = (6 + 4) / (2 * 1) = 5
First case: 5^x = 1
Ln(5^x) = Ln(1)
x.Ln(5) = 0
→ x = 0
Second case: 5^x = 5
5^x = 5^1
→ x = 1
Solution = { 0 ; 1 }
5^(x * 2) - [6 * 5^(x)] + 5 = 0 → you know that: x^(a * b) = (x^a)^b
[5^(x)]² - 6 * 5^(x) + 5 = 0 → let: X = 5^x → where X > 0 of course
X² - 6X + 5 = 0
Polynomial like: ax² + bx + c, where:
a = 1
b = - 6
c = 5
Δ = b² - 4ac (discriminant)
Δ = (- 6)² - 4(1 * 5) = 36 - 20 = 16 = 4²
X1 = (- b - √Δ) / 2a = (6 - 4) / (2 * 1) = 1
X2 = (- b + √Δ) / 2a = (6 + 4) / (2 * 1) = 5
First case: 5^x = 1
Ln(5^x) = Ln(1)
x.Ln(5) = 0
→ x = 0
Second case: 5^x = 5
5^x = 5^1
→ x = 1
Solution = { 0 ; 1 }