Tickbox quiz #3

GRE Quant Problem Solving
1

Tickbox quiz 3 #19:
if a and b are negative integers, which always results in a negative number.

One of the options is a^b which is not a correct selection. I had chosen it as correct thinking that if it had parentheses (a)^b, then it would become positive, but as it is without parentheses it would be a negative number. If there is a variable in a problem like this as opposed to an explicit number, are we meant to just assume it would have parentheses?

2

(-3)^{-2} = \frac{1}{(-3)^2} = \frac 19

3

Yes I see that but I’m asking if we would always assume that the variable is in parantheses. because if it were written as 1 / -3^9 it would be 1/-9.

5

Well, it’s a^b, and since a = -3, the exponentiation is applied to -3, not just 3.