Question

What is an equation in point-slope form of the line that passes through (-7. 1) and (-3, 9)?

A. y+ 3 = 2(x-9)
B. y-3 = 2(x +9)
C. y + 9 = 2(x - 3)
D. y - 9 = 2(x + 3)

Answer 1

D

Explanation:

general equation of point slope is

(y-y1)=m(x-x1) where

m-is the slope

(x1,x2) is any point that belongs to the line

For (-7,1) and (-3, 9) you have to

first find the slope

m= (y2-y1) /(x2-x1) = (9-1)/ (-3- -7)= 8/(-3+7) = 8/4 =2

second pick any of your 2 given points for example (-3, 9)

now you substitute m=2, and (-3,9) in your general equation

(y-9) = 2( x- -3) so the equation is (x-9) =2(x+3)