# Thread: Equation of a line

1. ## Equation of a line

Write the equation of the line that contains the specified points in the form ax+by=c, where a and b are integers.

1. (5,-5) and (2,4)

Thanks so much for any help!

2. Originally Posted by live_laugh_luv27
Write the equation of the line that contains the specified points in the form ax+by=c, where a and b are integers.

1. (5,-5) and (2,4)

Thanks so much for any help!
Hello live_laugh_luv27,

You know you have to find the slope of the line containing those two points, don't you?

$m=\frac{y_2=y_1}{x_2-x_1}$

Do that first. Next, use the point-slope form of the linear equation and do some substituting.

$y-y_1=m(x-x_1)$

You know what the slope (m) is from the formula above, right?

Use one of your points to substitute in for $x_1$ and $y_1$.

Move things around until you get it in your desired standard form:

$ax+by=c$ where c is a constant.

Good luck.

3. Originally Posted by live_laugh_luv27
Write the equation of the line that contains the specified points in the form ax+by=c, where a and b are integers.

1. (5,-5) and (2,4)
Well, what have you done?
Tell us the slope of this line.

4. ## Thanks

Thanks so much!
Sorry it took so long...
but I came up with y = -3x + 10, and switched it around to get 3x + y = 10. So, I got a = 3 and b = 1.
Is this correct? Thanks again!

5. Originally Posted by live_laugh_luv27
Thanks so much!
Sorry it took so long...
but I came up with y = -3x + 10, and switched it around to get 3x + y = 10. So, I got a = 3 and b = 1.
Is this correct? Thanks again!
You are the man!! Correctamundo!.