SOLUTION: Find the equation of the line passing through the points ( - 4, 8) and (5, -1). Also find the equation of the straight line perpendicular to the line you find above and passin

Algebra ->  Coordinate Systems and Linear Equations  -> Lessons -> SOLUTION: Find the equation of the line passing through the points ( - 4, 8) and (5, -1). Also find the equation of the straight line perpendicular to the line you find above and passin      Log On


   

Question 153486: Find the equation of the line passing through the points ( - 4, 8) and (5, -1).
Also find the equation of the straight line perpendicular to the line you find above and passing through the point ( -3, -8).
Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
(-4,8) (5,-1)
slope=(y2-y1)/(x2-x1)
(-1-8)/(5+4)=-9/8 slope.
Y=mX+b
8=-9/8*-4+b
8=36/8+b
8=9/2+b
b=9-9/2
b=9/2 THE Y INTERCEPT.
Y=-9X/8+9/2 (RED LINE)
THE PERPENDICULAR LINE HAS A SLOPE=8/9 THROUGH (-3,-8)
-8=8/9*-3+b
-8=-24/9+b
b=-8+24/9
b=(-8*9+24)/9
b=(-72+24)/9
b=-48/9=-16/3
Y=8X/9-16/3 (GREEN LINE)
+graph%28+300%2C+200%2C+-6%2C+5%2C+-10%2C+10%2C+-9X%2F8+%2B9%2F2%2C+8X%2F9+-16%2F3%29+ (graph 300x200 pixels, x from -6 to 5, y from -10 to 10, of TWO functions -9X/8 +9/2 and 8X/9 -16/3).