2a) it is not a direct variation
2b) it is a direct variation; k = -4
Explanantion:
For the relationship to be a direct variation, it must follow the formula:
y = kx
where k = constant of variation
k = y/x
The value of k must be constant for all
for 2a:
when y = 0, x = -3
k = 0/-3 = 0
when y = 3, x = 1
k = 3/1 = 3
when y = 6, x = 3
k = 6/3 = 2
From the above, the value of k is not constant. hence, it is not a direct variation
for 2b:
when y = -10, x = 2.5
k = -10/2.5 = -4
when y = -20, x = 5
k = -20/5 = -4
when y = -30, x = 7.5
k = -30/7.5 = -4
From the above, the value of k is constant. Hence, it is a direct variation
The constant of variation, k = -4