we have that
y = –x + 8
and
4x + 4y = 12
we know that
if two lines are perpendicular
so
m1*m2=-1
step 1
find the slope of the lines
y = –x + 8 -------> m1=-1
4x + 4y = 12-----> x+y=3 (divided by 4 all expression)
y=3-x
m2=-1
therefore
m1=m2
the lines are parallel
the answer is
No; their slopes are not opposite reciprocals.
see the attached figure