Question

PLEASE HELP WITH THIS PRE-CAL QUESTION...



The equation of line n is 8x-14y+3=0 What is k if the graphs of n and kx-7y+10=0 are perpendicular?

Answer 1

Have you gotten any progress with this or are you just stumped?

Answer 2

\[8x-14y+3=0\]
I turned it into slope intertcept form
\[y=\frac{ 4 }{ 7 } x+\frac{ 3 }{ 14 }\]
I don't exactly know what to do now

Answer 3

change the other equation into slope intercept form

Answer 4

Do you know the relationship between slopes that are perpendicular?

Answer 5

perpendicular means that it has the exact opposite slope
y=mx+b
m=slope
b=y-intercept

Answer 6

I got y = k/7 x + 10/7

Answer 7

@killerdime20 Not exactly.

Answer 8

i know that it has something to do with the slope and its perpendicular is using the reversed and using the opposite sign. Right?

Answer 9

The negative reciprocal, yes. That means that if you set the negative reciprocal of the slope in y=4x/7+3/14 and set it equal to k/7, you can solve for k.

Answer 10

thats what i meant. sorry for not being clear about it

Answer 11

I'm wondering where the k/7 came from though

Answer 12

k/7 is the slope of the perpendicular equation that you derived.

Answer 13

Oh yeah I understand now

Answer 14

Theoretically, if you find the negative reciprocal of A's slope, you'll have the slope of B.

Answer 15

So Do I set them equal to eachother?

Answer 16

It should look like this: