SOLUTION: An equation of a line through (-4, -5) which is perpendicular to the line y=4 x +3 has the following slope and b: slope: b: Tried multiple times and still

Algebra ->  Equations -> SOLUTION: An equation of a line through (-4, -5) which is perpendicular to the line y=4 x +3 has the following slope and b: slope: b: Tried multiple times and still      Log On


   

Question 990050: An equation of a line through (-4, -5) which is perpendicular to the line y=4 x +3 has the following slope and b:

slope:

b:
Tried multiple times and still getting the wrong answer some how :/
Equation formulas i used:
y1-y2/x1-x2
y-y1=m(x-x1)
Please help
Found 2 solutions by Alan3354, Edwin McCravy:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
An equation of a line through (-4, -5) which is perpendicular to the line y=4 x +3 has the following slope and b:

slope:

b:
Tried multiple times and still getting the wrong answer some how :/
Equation formulas i used:
y1-y2/x1-x2
y-y1=m(x-x1)
==========================
slope = -1/4
---
y+5 = (-1/4)(x+4)
y + 5 = (-1/4)(x - 1) = (-1/4)x + 1/4
y = (-1/4)x - 19/4
b = -19/4

Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
The slope formula (y1-y2)/(x1-x2) won't do you any good here.
[But you should learn that numerators and denominators that 
contain more than one number or one letter MUST be enclosed
withing parentheses to tell where the numerators and denominators
begin and end.]

You have to get the slope from this given line 

y = 4x + 3

Its slope of it is 4 because you compare it to y = mx + b and m = 4

A line that is perpendicular to a line with slope 4 has slope formed by:

1. Taking the reciprocal of 4, which is 1/4.  That's because a "run" becomes
   a "rise" and vice-versa.
2. Changing the sign to -1/4 because if a line goes uphill to the right, a 
   line perpendicular to it will go downhill, and vice-versa.

So the slope of the desired line is -1/4.  Now you can substitute m = -1/4
and (x1,y1) = (-4, -5)

  y - y1 = m(x - x1)
y - (-5) = -1/4(x - (-4))
   y + 5 = -1/4(x + 4)
   y + 5 = -1/4x - 1
       y = -1/4x - 6

Edwin