Real Number Properties II - PrepSwift Quiz

[asmota2704]

Hello! I can’t seem to understand the solution to Q3 on the PrepSwift Quiz for Real Number Properties II.

The question states that a and b are negative integers, which of the following must also be negative?

One of the options in a^b which per the solution can be positive. If a is -5 and b is -2 for example:

a^b = -5^-2 = - (1/5^2) = -1/25.

The solution says: a^b can be positive as well. For example, (−5) = 25, which is positive. I know I’m probably missing something silly but can’t figure out what.

Thank you in advance for your help!

[Leaderboard]

@asmota2704

One of the options in a^b which per the solution can be positive. If a is -5 and b is -2 for example:

a^b = -5^-2 = - (1/5^2) = -1/25.

There’s where you go wrong. (-5)^{-2} is positive - can you see why?

[asmota2704]

Ah I see what you mean. Parentheses matter, eh? I solved for -5^-2 instead of (-5)^-2. Thank you!