Y= -2x+14
Steps:
M is gradient
B is the second point from 1 of the pair of points given in the question
A is the first point from one of the pair of points given in the question (same pair must be used for point A and point B)
M= y2-y1/ x2-x1
M= 4-2/ 5-6
M= 2/-1
M= -2
Y-b=M(x-a)
Y-2= -2 (x-6)
Y-2= -2x+12
Y= -2x+14