Which equations show direct variation between a and b? Choose all answers that are correct.

a. b = 0.7a

b. b = 1/8a-3

c. 5 (1/a) = b

d. 1a=b

A.) b = 0.7a

d) 1a = b

These two equation shows the direct variation. with the coefficient of a as the constant of variation.

y = kx; where k is the constant of variation. y directly varies with x at the rate of k.

b = 0.7a where b represents y; a represents x; and 0.7 represents k.

1a = b where b represents y; a represents x; and 1 represents k.