SOLUTION: How would you answer: Write the equation of the line containing the points of (-1,-2) and (-2,-4). How would you answer: Write the equation of the line perpendicular to 3y

Algebra ->  Linear-equations -> SOLUTION: How would you answer: Write the equation of the line containing the points of (-1,-2) and (-2,-4). How would you answer: Write the equation of the line perpendicular to 3y      Log On


   



Question 617756: How would you answer:
Write the equation of the line containing the points of (-1,-2) and (-2,-4).
How would you answer:
Write the equation of the line perpendicular to 3y-2x-5=0 containing the point (-4,5).
I have a FINAL EXAM tomorrow and I need at least a 90 on it.

Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
first find the slope ___ m = (-4 - -2) / (-2 - -1) = -2 / -1 = 2

use the slope-intercept equation ___ y = mx + b
___ put in the slope, then use one of the given points to find the intercept (b)
___ y = 2x + b ___ (-2) = 2(-1) + b ___ -2 = -2 + b ___ 0 = b
___ so the equation is ___ y = 2x


start the same way, by finding the slope; solving for y to get the slope intercept form

3y = 2x + 5 ___ y = (2/3)x + (5/3)

the slope of the perpendicular is the negative reciprocal ___ y = (-3/2)x + b

again, use the given point to find b ___ (5) = (-3/2)(-4) + b ___ 5 = 6 + b ___ -1 = b
___ so the equation is ___ y = (-3/2)x - 1


good luck on the exam