Question

The lines represented by the equations 4y + 4x = 8 and y - x = -2 are

neither parallel nor perpendicular
the same line
perpendicular
parallel

Answer 1

4 y = -4 x + 8 or y = -x + 2

y - x = -2 or y = x - 2

using the standard form for a line y = m x + b

We see that in one equation m = -1 and in the other m' = +1

this is the condition for perpendicular lines