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?

a. -8
b. 14
c. -49/4
d. 16/5

Please select the best answer from the choices provided
A
B
C
D

Answer 1

First put the given equations into the form, y = mx + c, as follows:

`y=(4)/(7)x+(3)/(14)`

`y=(k)/(7)x+(10)/(7)`
For perpendicularity, the product of the slopes must equal negative one.

`(k)/(7)*(4)/(7)=-1`
Solving for k, we get:

`k=-(49)/(4)`
The correct choice is C.