what is -a^-2 if a=-5?

A.)-25
B.)25
C.)-1/25
D.)1/25

I think it is D.

Please help.

4 answers

a^-2 = 1/a^2, so
(C)
even though that is -a? you wrote it as positive a to the -2 power = 1/a to the 2nd ...just making sure
yes. the "-" is done after the ^-2

-a^-2 = -(a^-2) = -1/a^2

(-a)^-2 = 1/(-a)^2 = 1/a^2
Thank you for the explanation - that really helps....