Question

What is the slope of the line that is perpendicular to the line whose equation is 2x - y = 7?
-2
-1/2
1/2
2

Answer 1

2?

Answer 2

Start by solving for y


What do you get when you do so?

Answer 3

No, 2 is not the slope of the perpendicular line

Answer 4

But....2 is the slope of 2x-y = 7, here's why


2x - y = 7

-y = 7 - 2x

-y = -2x + 7

y = -2x/(-1) + 7/(-1)

y = 2x - 7


So we can see that the slope of y = 2x - 7 is 2

Answer 5

Note that the equation of a perpendicular line has a slope which is the negative reciprocal of the original line.

Answer 6

Once you have the slope of 2x - y = 7, which is 2, you then flip the fraction to get 1/2. Afterwards, you change the sign to get -1/2

So the slope of the perpendicular line is -1/2

Answer 7

thank you guys