Question

On a number line, a number, b, is located the same distance from 0 as another number, a, but in the opposite

direction. The number b varies directly with the number a. For example b = 22 when a = -22. Which
equation represents this direct variation between a and b?
b=-a
-b=-a
b-a=0
b(-a) = 0

Answer 1

b = -a

Explanation:

Since a and b are equally distant to zero but in opposite directions, a and b are opposites, or additive inverses.

The sum of additive inverses is zero.

a + b = 0

b = -a