Question

Streets on a city map are described by lines.



Which pair of lines would describe streets on the map that are neither parallel nor perpendicular?

A.
{
y
=
3
x
+
2
y
=
3
x
+
3

B.
{
y
=
1
3
x
+
7
y
=
3
x
+
7

C.
{
y
=
x
+
6
y
=
−
x
+
6

D.
{
y
=
−
5
x
+
8
y
=
1
5
x
+
5

Answer 1

B

Slopes are 1/3 and 3. They are not equal (so not parallel) and their product is 1 (not −1), so they are not perpendicular.