Solving Exponential Equations: A Step-by-Step Guide
This article will guide you through solving the exponential equation:
(5/3)^(x+1) * (9/25)^(x^2 + 2x - 11) = (5/3)^9
Let's break down the solution step-by-step:
1. Express All Bases as the Same Value
Our goal is to have all terms with the same base. Notice that (9/25) can be expressed as (3/5)^2. Substituting this into the equation gives us:
(5/3)^(x+1) * ( (3/5)^2 )^(x^2 + 2x - 11) = (5/3)^9
2. Simplify Using Power of a Power Rule
We can simplify the left-hand side using the power of a power rule: (a^m)^n = a^(m*n). Applying this:
(5/3)^(x+1) * (3/5)^(2x^2 + 4x - 22) = (5/3)^9
3. Express All Terms with the Same Base
To further simplify, let's express (3/5) as (5/3)^(-1):
(5/3)^(x+1) * ( (5/3)^(-1) )^(2x^2 + 4x - 22) = (5/3)^9
Applying the power of a power rule again:
(5/3)^(x+1) * (5/3)^(-2x^2 - 4x + 22) = (5/3)^9
4. Combine Exponents
Now, we can combine the terms on the left-hand side using the rule: a^m * a^n = a^(m+n):
(5/3)^(x+1 - 2x^2 - 4x + 22) = (5/3)^9
Simplifying the exponent:
(5/3)^(-2x^2 - 3x + 23) = (5/3)^9
5. Solve for x
Since the bases are the same, we can equate the exponents:
-2x^2 - 3x + 23 = 9
Rearranging the equation to form a quadratic:
2x^2 + 3x - 14 = 0
Factoring the quadratic equation:
(2x - 7)(x + 2) = 0
Therefore, the solutions for x are:
x = 7/2 or x = -2
Conclusion
By applying the rules of exponents and simplifying the equation, we successfully solved for x. The solutions to the equation are x = 7/2 and x = -2.