The exponential equation is solved as follows;
[tex]\begin{gathered} 2^{x-1}=8 \\ 2^{x-1}=2^3 \\ Note\text{ that both sides of the equation has 2 as the base, therefore} \\ \text{If 2=2, then x-1=3} \\ 2^{x-1}=2^3 \\ x-1=3 \\ x=3+1 \\ x=4 \end{gathered}[/tex]
The third option is the correct answer
