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 = 2 3/4 when a = –2 3/4. Which equation represents this direct variation between a and b?

b = –a
–b = –a
b – a = 0
b(–a) = 0

Answer 1

a on edge

Explanation:

Answer 2

The correct answer option is b = -a.

Explanation:

We know that a number b is located the same distance from 0 as another number, a, but in the opposite direction.

So, The equation will be b = -a which is the same as writing b = -1 * a.

Here, the negative sign with the 'a' will change it from positive to negative, or vice versa.

Recall how,

negative times positive is negative; and

negative times negative is positive.