Chapter 14, Question 4 on page 551 is about exponents and roots:
Quantity A
square-root(3) + square-root (6)
Quantity B
square-root (9)
THEIR answer: Quantity A because...
"You may NOT add root(3) and root(6) to get root (9), but you can simply put each value in your calculator. Root(3)=1.732... and root(6)=2.449..., and their sum is 4.18. Since Quantity B is root(9)=3, quantity A is larger."
I see a problem with this logic because root(3) = +/- 1.732 and root(6) = +/- 2.449, whereas root(9) = +/- 3, which means that when added you have four options for Quantity A (+/- 4.181 and +/- 0.717) and two for Quantity B (+/- 3), hence it is impossible to tell, hence my answer would be D.
Now there are NO absolute signs anywhere on this problem.
Are we, on the real GRE, NOT to consider that for a root there are two solutions?
Thanks in advance for your help.