Answer:
b = -a
Step-by-step explanation:
We know that:
On a number line, the distance between 0 and b is the same distance that between 0 and a (but b and a are in opposite sides of zero).
And we know that, for example, when:
b = 2, a = -2
Remember that the distance between two values is given by:
|n - m|
Then the distance between 0 and b is:
|0 - b|
and the distance between 0 and a is:
|0 - a|
we have:
|-b| = |-a|
|b| = |a|
But the numbers are in opposite sides of the zero, so one must be positive and the other negative, then we can conclude that:
b = -a
or
-b = a
(these are equivalent)
Then the correct option is the first option:
b = -a
