Darrell B. answered • 10/02/12

Need Help With Math, Computers or just about anything?

The equation of a line is

y-y1=m(x-x1) ,where y1 is your y-cord, m is your slope and x1 is your x-cord.

the information you provided was m=2, (2,-2)

now plug in

y-(-2)=2(x-2)

now solve for y to put it in the form of y=mx+b where m is your slope and b is your y intercept

y+2=2x-4

y=2x-6

Helga M.

Alejandro is absolutely right. But here are a few more comments to help you understand.

y = mx + b

is called the slope intercept form because you can read off directly the slope (m) and the intercept of the y axis (b).

When you are given the slope and a point, you use the points x and y coordinate as the x and y value in this equation and solve for b.

If you are given two points, you first determine the slope from both points and then use one of the points (it doesn't matter which) to find the y intercept.

So let's say you were given (2, -2) and (5, 4)

Calculate the slope as (y1-y2)/(x1-x2) = (-2-4)/2-5) = -6/-3 = 2

and then continue as Alejandro described.

10/01/12