196k views
5 votes
Write an equation in slope-intercept form for the line that passes through the given points and is (a) parallel to the given line and (b) perpendicular to the given line. 1. (-7,3);x=4

2.(5,-1);y=4x-7
Please help!!

1 Answer

7 votes
Remark
This is costing you an awful lot of points, but it is a little hard to read. If I'm not interpreting it correctly, leave some sort of note below my answer.

Question One
In the first question you want a line that is parallel to x = 4 and goes through the point (-7,3). If I'm reading this correctly then the line you want is x = -7. You only need the x value of the given point. I'll put a graph there to show you what it looks like on a grid. The graph is the left one for this question.

Question Two
Here I think you want the line going through (5,-1) and perpendicular to y = 4x - 7. I will make a graph for that one as well.

Begin with the slope
Two lines are perpendicular to each other if their slopes multiply to - 1
Given slope (m1) = 4
perpendicular slope = m2

Formula
m1 * m2 = - 1
4 * m2 = -1 Divide by 4
m2 = -1/4

So far what you have is
y = (-1/4)x + b

Now use the given point to solve for b
x = 5
y = - 1
b = ??

-1 = (-1/4)*5 + b
-1 = -5/4 + b Add 5/4 to both sides
-1 + 5/4 + b Make -1 into -4/4
b = -4/4 + 5/4
b = (-4 + 5)/4
b = 1/4

So the line that you want is
y = (-1/4) x + 1/4

Answers
One: x = - 7
Two: y = (-1/4)x + 1/4

Note
The right graph is of y = 4x - 7 and y = (-1/4)x + 1/4
Write an equation in slope-intercept form for the line that passes through the given-example-1
Write an equation in slope-intercept form for the line that passes through the given-example-2
User Discky
by
7.9k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories