Answer:
C
Step-by-step explanation:
In the equation y = -x - 4, the gradient is -1.
While in the second equation,
5x + 5y = 20
y = -x + 4
So the gradient is -1 too
Both sides are not perpendicular to each other because if you apply the formula, m1m2 = -1, and if substitute both gradient, (-1)(-1) = 1 ≠ -1
Therefore, no they are not perpendicular but parallel instead.