Question

What is the value of the expression?

7^-3x7^9/7^-8


A.
714

B.
72

C.
7−14

D.
7−2

Answer 1

$Use:\\a^n\cdot a^m=a^{n+m}\ and\ a^n:a^m=a^{n-m}\\\\7^{-3}\cdot\dfrac{7^9}{7^{-8}}=7^{-3}\cdot7^{9-(-8)}=7^{-3+9+8}=7^{14}\\\\Answer:\boxed{A.\ 7^{14}}$