Answer:
Y = negative x + 9
Explanation:
Find the equation of the line for side S-
m= 4-1/1-4 = 3/-3 = -1
The Gradient is -1
Since parallel lines share the same gradient, it should be either of the first two options.
We can see side Q shares the same gradient: 3-6/6-3= -1
Find the equation of the line of side Q-
y-y1= m(x-x1)
y-6= -1(x-3)
y-6=-x+3
y= -x+9