Question

10. Which of the following is equivalent to thisexpression?72.7-4Tutor

Answer 1

To answer this question we need to remember that:

`a^ma^n=a^(m+n)`

then:

`\begin{gathered} 7^2\cdot7^(-4)=7^(2-4) \\ =7^(-2) \end{gathered}`

now we need to remember that:

`a^(-n)=(1)/(a^n)`

hence:

`7^(-2)=(1)/(7^2)`

Therefore:

`7^(-4)\cdot7^2=(1)/(7^2)`

and the asnwer is A.