Question

Direction. The number b varies directly with the number a. For example b = 2 when a = -2

-2. Which equation
=
4
represents this direct variation between a and b?
b = -a
-b = -a
ОООС
b-a= 0
b(-a) = 0

Answer 1

b = - a

Explanation:

given b varies directly with a then the equation relating them is

b = ka ← k is the constant of variation

to find k use the condition b = 2 when a = - 2 , then

2 = - 2k ( divide both sides by - 2 )

- 1 = k

then

b = - a ← equation of variation