Are the lines y=-x-2 and 4x+4y=16 perpendicular? explain

a. yes; their slopes have product -1
b. no; their slopes are not opposite reciprocals
c. yes; their slopes are equal
d. no; their slopes are not equal

First rearrange the second equation into the form y = mx + b (where m = slopeof the graph of the equation):-

4x + 4y = 16 
4y = -4x + 16
y = -x + 4
now compare the slope with 
y = x - 2

slope of the first one is -1 and slope of the second is 1

slopes have product of 18-1 = -1  so the 2 lines are pependicukar

A is correct