Question

A city map is laid out on a coordinate plane. Elm Street is described by the line x + 2y = -6. Oak street intersects Elm Street at an right angle. Which of the following could be the equation for Oak Street?

a. 2x + y = 5
b. -2x + y = 3
c. x + 2y = 4
d. -x - 2y = 8

My answer: d?

Answer 1

see later post