Question

Find the equation of the line that goes through the points (-2, -1) and (2, -5).

Answer 1

to write the equation of a line you need a slope and a y intercept,

Do you know how to find the slope?

Answer 2

y=mx+b

Answer 3

thats the slope intercept form of a line.

Slope formula given two points is

y2-y1/x2-x1

-5 --1/2 --1

tell me what you get

Answer 4

3/2

Answer 5

-5 - -1 -5 +1 = -4 minus a neg, is same as addition
________
2 - - 2 2 + 2 = 4

slope is -4/4, = -1 do you see where I got that?

Answer 6

Yes, I didn't see the - in front of the 5

Answer 7

now that you have a slope, how do you find the equation?

using point slope or y = mx + b? your choice

Answer 8

y=mx+b

Answer 9

pick one of the points doesnt matter which one....which ever..

Answer 10

x y
say (-2, -1), subsitute this and slope into y = mx + b

-1 = -1(-2) + b , b is the y intercept, solve for b

Answer 11

(-2,-1)
y=mx+b
-1=-1(-2)+b
-1=2+b
-2 -2
-3=b
b=-3

Answer 12

great!
now you have a slope and a y intercpet for your line.
m = -1, b = -3, just substitute them into y = mx + b

y = -1x - 3 or y = -x -3

Answer 13

ok. Thanks