Question

Find the line that contains the point P = (2,6) and is parallel to the line y = -4x + 26

Answer 1

can you find slope of line y = -4x + 26 ?

Answer 2

ok

Answer 3

just compare it to y=mx+c , where m is the slope.

Answer 4

-4

Answer 5

yes.

Answer 6

now parallel lines have same slope, so the slope of your line will also be -4, right ?

Answer 7

hmm yea

Answer 8

m will be same

Answer 9

now u have a point and slope, can you find the equation ?

Answer 10

I see lets try

Answer 11

know the point slope form of equation of line ? or should i mention it ?

Answer 12

Making a sketch may help.

Answer 13

y=mx+b I replace y and x with 2 and 6 ? but then I would replace b too with 6 and there would be no equation, so I would do y=-4x+6 but that is still not the answer

Answer 14

or it is indeed the answer ;p

Answer 15

nah its not

Answer 16

the form is y-y1 = m (x-x1)
where point x1,y1 = 2,6 and m=-4

Answer 17

isn't it y = mx + b ?

Answer 18

thats slope intercept form :y=mx+b
you have a point and slope , so, y-y1 = m (x-x1)

Answer 19

I see

Answer 20

"but then I would replace b too with 6" here is your mistake... you are solving for b in y=mx+b

Answer 21

yea thats what I did indeed

Answer 22

You do not replace b with 6

Answer 23

because 'b' is y-intercept which is not given.

Answer 24

I got y = mx - 2m +6

Answer 25

You replace y with 6

Answer 26

yes, just put m=-4 because you know it!

Answer 27

:D

Answer 28

y = -4x + 14 its correct :))

Answer 29

:D
good work!

Answer 30

thanks

Answer 31

welcome ^_^

Answer 32

now I have a similar one that is perpendicular this time instead of parallel

Answer 33

I guess in that case m is not the same to work with that

Answer 34

so you need to know that product of slopes of perpendicular lines = -1

Answer 35

just to find slope.

Answer 36

when you say "the product" of slopes you mean m1 + m2 = -1 ?

Answer 37

product = multiplication :P
m1 * m2 = -1

Answer 38

aaah I see ok ^^

Answer 39

It might be easier to think that the second slope will be -1/m if m is the slope of the first line...

Answer 40

Completely equivalent to @hartnn's statement, but easier for some to grasp...

Answer 41

yes^

Answer 42

Nice one whpalmer sounds easier