Answer :

To solve the equation [tex]\(8^{3^{x+1}} = 2^{9^{x-1}}\)[/tex], we can follow these steps:

1. Express Both Sides with the Same Base:
- Notice that 8 can be expressed as [tex]\(2^3\)[/tex] and 9 can be expressed as [tex]\(3^2\)[/tex]. Let's rewrite both sides accordingly.

[tex]\[ 8^{3^{x+1}} = (2^3)^{3^{x+1}} \][/tex]
and
[tex]\[ 2^{9^{x-1}} = 2^{(3^2)^{x-1}} \][/tex]

2. Simplify the Exponents:
- Apply the property of exponents [tex]\((a^m)^n = a^{m \cdot n}\)[/tex].

[tex]\[ (2^3)^{3^{x+1}} = 2^{3 \cdot 3^{x+1}} \][/tex]
and
[tex]\[ 2^{(3^2)^{x-1}} = 2^{(3^{2(x-1)})} \][/tex]
Simplify inside the exponent on the right-hand side:
[tex]\[ 2^{(3^{2(x-1)})} = 2^{(3^{2x-2})} \][/tex]

3. Set Exponents Equal to Each Other:
- Since the bases are the same (both base 2), we can set the exponents equal to each other:

[tex]\[ 3 \cdot 3^{x+1} = 3^{2x-2} \][/tex]

4. Simplify the Equation:
- Recognize that [tex]\(3^{x+1} = 3 \cdot 3^x\)[/tex]. Replace this back into the equation:

[tex]\[ 3 \cdot 3 \cdot 3^x = 3^{2x-2} \][/tex]
Simplify the left-hand side:
[tex]\[ 3^2 \cdot 3^x = 3^{2x-2} \][/tex]
[tex]\[ 3^{2 + x} = 3^{2x-2} \][/tex]

5. Equate the Exponents:
- Since the bases are the same, we can set the exponents equal to each other:

[tex]\[ 2 + x = 2x - 2 \][/tex]

6. Solve for [tex]\(x\)[/tex]:
- Rearrange the equation to solve for [tex]\(x\)[/tex]:

[tex]\[ 2 + x = 2x - 2 \][/tex]
[tex]\[ 2 + 2 = 2x - x \][/tex]
[tex]\[ 4 = x \][/tex]

So, the solution to the equation [tex]\(8^{3^{x+1}} = 2^{9^{x-1}}\)[/tex] is [tex]\(x = 4\)[/tex].