Question

If |a| = -a and |b| = -b, then a-b=
A) |a| +|b|
B) |a|-|b|
C) -|a|+|b|
D) -|a|-|b|

I don't get this, if you square root any number, how does it become negative??

Answer 1

who's talking about square roots? These are absolute values.

|a| = -a, so a = -|a|
same for b. So,

a-b = -|a| - (-|b|)
= -|a| + |b|

Answer 2

Ohh I mixed them up, thanks!