Answer:
the lines are perpendicular
Step-by-step explanation:
if they are perpendicular the products of their gradients would be -1
the gradient of y=-x-6 is -1
the second equation needs to written to conform to y=mx+c
hence, 3x-3y=9
3x-9=3y
y=3x-9/3=x-3.the gradient of this line is 1
1x-1= -1
