Question

Help me please! I don't know how to do this..
write the equation of the line (in slope intercept form) that is parallel to the given line but which passes through the point (-3,4)
Also write the equation of the line line (in slop intercept form) that is perpendicular to the given line but which passes through (-3, 4)

the "given" line it's talking about is y=-2x+1 or (-4,7) and (1,-3)

Answer 1

can you identify "slope " of the given line?

Answer 2

this is the info you will need to solve this:
parallel lines have the same slope;

if two lines are perpendicular, the product of their slopes is -1

Answer 3

so the parallel line has the same slope as my original line? this being -2? so how do I write the equations in slope intercept form?

Answer 4

Y=MX + c is the slope intercept form,

Answer 5

M is slope

Answer 6

so for my parallel line it would be y=-2+1 and my perpendicular line would be y=-1+1?

Answer 7

No, where did the x go?

Answer 8

Do the parallel lines first

Answer 9

oops so parellel would be y=-2x+2 and perpendicular would be y=-1x+1?

Answer 10

For the parallel line
Y=-2x + c

U have to substitute the point -3,4 to find c

Answer 11

I got y=-2x+1.5

Answer 12

No
Substitute x=-3 and y=4
And find c

Answer 13

I got y=-2x+2....

Answer 14

Yea

Answer 15

so that's my parallel line. and my perpendicular line is y=-1x+1??

Answer 16

No
Product of slopes of perpendicular lines =-1

Answer 17

i'm lost...

Answer 18

What is the slope of the given line?

Answer 19

-2

Answer 20

Let slope of perpendicular line be 'm'

-2*m=?

Answer 21

4....

Answer 22

When the slope of perpendicular lines are multiplied, we get -1

Answer 23

-2*m=?

Answer 24

I'm confused...

Answer 25

What's confusing?

Answer 26

I just don't understand what my equation is for my perpendicular line,.

Answer 27

To find that, u first need to find slope of the perpendicular line

Answer 28

Thats what I'm asking u to find

Answer 29

I thought the slope was -1?

Answer 30

How is the slope-1

Answer 31

I thought you said it was... how do I find the slope of that line?

Answer 32

If two lines are perpendicular, the product of their slopes is -1

Answer 33

okay......?

Answer 34

This means, slope of given line multiplied by slope of the line u want to find gives -1

Answer 35

I don't understand what to solve here...

Answer 36

U have to find "slope" of the required line,

U can find that by using the property: slope of required line multiplied by slope of given line =-1

Answer 37

Slope of given line: -2
Slope of required line: m

-2*m=-1

Answer 38

0.5???

Answer 39

yes

Answer 40

so what do I do now?

Answer 41

y=0.5x + c

find c by substituting the point (-3,4)

Answer 42

y=0.5x+0.375?

Answer 43

no

Answer 44

what am I doing wrong?

Answer 45

substitute
x=-3
y=4

can you do that and re-write the equation?

Answer 46

\[4=0.5(-3)+c\]
0.5 multiplied by -3
\[4=1.5+c\]
Both sides divided by 4
\[-0.375c\]

Answer 47

I got 5.5

Answer 48

thanks for all your help!

Answer 49

yes, its 5.5