B . A & b are parallel to each other
M = (y2 - y1)/(x2-x1)
= 2+5/-3-1
= 7/-4
= -7/4
It does represent a direct variation.
Direct variation: y = kx
y varies directly with x
Your equation 2y = 5x + 1 is in the form of y = kx but we need to divide out the 2 from 2y so we have the following
2y = 5x + 1
2y / 2 = 5 x/ 2 + 1/2
y = 5x / 2 + 1/2
y = kx
k = 5/2
k = constant of variation = 5/2