# Identify an equation in point-slope form for the line perpendicular toy=-2x + 8 that passes through

Identify an equation in point-slope form for the line perpendicular to y=-2x + 8 that passes through (-3,9).
O A. y - 9 =-2(x+3)
O B. y+3 (x-9)
O C. y-9 - (x+3)
O D. y + 9 = 2(x-3)

## This Post Has 6 Comments

1. j015 says:

If the line is perpendicular, then as a rule the gradient of the perpendicular line will be the negative inverse of the gradient of the line given.
Therefore the gradient of the perpendicular line would be 1/2
so now just substitute in the equation of a line (y=mx+c) where y and x are given by -3 and 9, and your new m=1/2
Hope this helps

The answer is A because the slope is -2 and that is the only one that shows -2 as a slope

3. kaitlyn0123 says:

y - 9 = 1/2(x + 3)

Step-by-step explanation:

For the equation y = -2x + 8, your slope, m, is -2. To find the slope for a line perpendicular to the original line, we do the opposite reciprocal of this number. The slope of the perpendicular line is 1/2.

Point-slope form is: y - y1 = m(x - x1) where x1 and y1 are the x- and y-coordinates of an ordered pair.

With this new slope for the perpendicular line, and the point we are given, we just plug in the info.

Your equation is: y - 9 = 1/2(x + 3)

4. apere655 says:

$y - 9 = \frac{1}{2}(x +3)$

Step-by-step explanation:

Given

Function; $y = -2x + 8$

Required

Find an equation perpendicular to the given function if it passes through (-3,9)

First, we need to determine the slope of:  $y = -2x + 8$

The slope intercept of an equation is in form;

$y = mx + b$

Where m represent the slope

Comparing  $y = m_1x + b$ to $y = -2x + 8$;

We'll have that

$m_1 = -2$

Going from there; we need to calculate the slope of the parallel line

The condition for parallel line is;

$m_1 * m_2 = -1$

Substitute $m_1 = -2$

$(-2) * m_2 = -1$

Divide both sides by -2

$m_2 =\frac{ -1}{-2}$

$m_2 =\frac{1}{2}$

The point slope form of a line is;

$y - y_1 = m_2(x - x_1)$

Where $(x_1,y_1) = (-3,9)$ and $m_2 =\frac{1}{2}$

$y - y_1 = m_2(x - x_1)$becomes

$y - 9 = \frac{1}{2}(x - (-3))$

Open the inner bracket

$y - 9 = \frac{1}{2}(x +3)$

Hence, the point slope form of the perpendicular line is:

$y - 9 = \frac{1}{2}(x +3)$

5. Siris420 says:

For this case we have the following linear equation:
$y = -2x + 8&10;$
As the lines are perpendicular, then the slope of the line is:
$m' = \frac{-1}{m}$
Where,
m: is the slope of the original line
Substituting values we have:
$m' = \frac{-1}{-2}$
Rewriting:
$m' = \frac{1}{2}$
Then, the equation in point-slope form is given by:
$y-yo = m '(x-xo)&10;$
Where,
(xo, yo): ordered pair that goes through the line.
Substituting values we have:
$y-9 = \frac{1}{2}(x+3)&#10;$

an equation in point-slope form for the line perpendicular to y = –2x + 8 that passes through (–3, 9) is:
$y-9 = \frac{1}{2}(x+3)$

6. fangkronos says:

A

-2 is the slope which goes after the equal sign