Understanding the Equation
To solve the equation 3^(x) - 3^(x-1) = 18, we need to first simplify it.
Rearranging the Terms
1. Notice that 3^(x-1) can be rewritten as 3^x / 3.
2. Hence, the equation can be transformed to:
- 3^(x) - (3^(x)/3) = 18
Finding a Common Denominator
3. To combine the terms on the left side:
- Multiply the first term by 3:
- (3 * 3^(x)) / 3 - (3^(x)/3) = 18
- This simplifies to:
- (3 * 3^(x) - 3^(x)) / 3 = 18
Simplifying Further
4. Now, factor out 3^(x):
- (3^(x)(3 - 1)) / 3 = 18
- This further simplifies to:
- (2 * 3^(x)) / 3 = 18
Isolating 3^(x)
5. Multiply both sides by 3 to eliminate the denominator:
- 2 * 3^(x) = 54
6. Now, divide by 2:
- 3^(x) = 27
Finding the Value of x
7. Recognize that 27 can be rewritten as 3^3:
- So, 3^(x) = 3^3
8. Therefore, equating the exponents gives:
- x = 3
Conclusion
Hence, the value of x is 3, which corresponds to option 'C'.