[tex]4=2^2\\\\4^x=(2^2)^x=(2^x)^2=7^2=49\\\\4^x-1=49-1=48[/tex]
[tex]If\ is\ 4^{x-1},\ then\\\\4^{x-1}=\dfrac{4^x}{4}=\dfrac{49}{4}=12\frac{1}{4}[/tex]
[tex]Used:\\\dfrac{a^n}{a^m}=a^{n-m}[/tex]
Answer:
49/4
Step-by-step explanation:
4^x-1 = (2^x)^2/4 = 7^2/4 = 49/4
