Question

Write an equation of the line that is perpendicular to 2x + 4y = 6 and passes through the point (6,4).

A) y = 2x + 4
B) y = 2x - 8
C) y = -2x + 16
D) y = - 1/2x+4

Answer 1

B

Explanation:

First things first, to be perpendicular we need to have the slope reverse recripocal.

Let's convert the equation in to y = mx + b form.

We get..

y = -1/2x + 3/2

We know know we are looking for a slope of 2, since -1/2 flipped is 1/2 and the recripocal of 1/2 is 2.

We can eliminate C and D since they don't have a slope of two.

Let's substitute the coordinate value of (6,4) in to A

4 = 2(6) + 4.

Wrong!

Let's head on to b now!

4 = 2(6) - 8

4 = 12 -8

4 = 4!

So the answer is B

Phew, this took some time xD