To answer this question we need to remember that:
[tex]a^ma^n=a^{m+n}[/tex]then:
[tex]\begin{gathered} 7^2\cdot7^{-4}=7^{2-4} \\ =7^{-2} \end{gathered}[/tex]now we need to remember that:
[tex]a^{-n}=\frac{1}{a^n}[/tex]hence:
[tex]7^{-2}=\frac{1}{7^2}[/tex]Therefore:
[tex]7^{-4}\cdot7^2=\frac{1}{7^2}[/tex]and the asnwer is A.
