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?
O b=-a
O-b = -a. O b-a=0
Ob(-a) = 0
