How do you solve e^(2x)-5e^x+6=0?

1 Answer
Jan 13, 2017

x = ln (2), ln (3)

Explanation:

We have: e^(2 x) - 5 e^(x) + 6 = 0

Using the laws of exponents:

Rightarrow (e^(x))^(2) - 5 e^(x) + 6 = 0

Let's factorise the equation:

Rightarrow (e^(x))^(2) - 2 e^(x) - 3 e^(x) + 6 = 0

Rightarrow e^(x) (e^(x) - 2) - 3 (e^(x) - 2) = 0

Rightarrow (e^(x) - 2) (e^(x) - 3) = 0

Rightarrow e^(x) = 2, 3

Applying ln to both sides of the equation:

Rightarrow ln (e^(x)) = ln (2), ln (3)

Using the laws of logarithms:

Rightarrow x ln (e) = ln (2), ln (3)

therefore x = ln (2), ln (3)