Question

“Find the equation of the line passing through (8,-2) & (7,-4). Write your equation in point-slope AND slope intercept forms.
Point slope form using (8,-2) _____
Point slope form using (7,-4) _____

Slope intercept form: y=2x-18

Answer 1

We know that
the equation of the line in point-slope------------>  (y – y1) = m(x – x1)
the equation of the line in slope intercept forms. ----->  y =mx+b

find the slope m
point (8,-2) & (7,-4).
m=(y2-y1)/(x2-x1)---------> (-4+2)/(7-8)=-2/-1----------> m=2

Part A)
find the equation of the line in point-slope using (8,-2)
(y – y1) = m(x – x1)---------> (y-(-2)) = 2*(x – 8)-------> y+2=2x-16
y=2x-16-2--------> y=2x-18

Part B)
find the equation of the line in point-slope using (7,-4)
(y – y1) = m(x – x1)---------> (y-(-4)) = 2*(x – 7)-------> y+4=2x-14
y=2x-14-4--------> y=2x-18

Part C)
find the equation of the line in slope intercept forms
using (7,-4)
y=mx+b--------> -4=2*7+b----------> -4=14+b-----------> b=-18
then
y=2x-18

Part D)
find the equation of the line in slope intercept forms
using (8,-2)
y=mx+b--------> -2=2*8+b----------> -2=16+b-----------> b=-18
then
y=2x-18