-12=m(-8)+b

Question

The question asks - Write the equation in slope-intercept form for the line that satisfies the given conditions.

Contains (12,17) and (0,9)

Answer 1

Helo, Elena

 

I am going to solve this problem using a different point than Cara used. Just to illustrate the fact that you can do this problem in different ways.

 

We first need to find the slope.  In order to do that, we need two points.   The points are. (12,17) and (0,9).  I am going to call (12, 17) (x1,y1) and (0,9) will be (x2,y2)... In reality, it does not matter which point you called (x1, y1) and (x2, y2); you will still get the right answer for the slope. The formula for the slope,m

 

m=[y2-y1]/ [x2-x1]             Substituting. Be careful!!!

m=[(9)-(17)]/[(0)-(12)]       Subtracting

m=[-8]/[-12]= 8/12= 2/3

So, the slope is 2/3.

 

Now, we are ready to use the point-slope form.   For this problem, I will choose, (12,17) as (x1,y1) and, of course, m= 2/3

 

The point slope form is as follows:

y-y1  =  m [ x- x1]                  Substituting

y-17  = 2/3[x-12]                    Using the distributive property

y-17  = (2/3)x- 8                       (2/3)(12/1)=24/3=8

  +17              + 17                   Adding 17 to both sides

      y= (2/3)x + 9

This should the equation of the line in the slope intercept form.  

 

Glad to help and thanks for posting. Take care.

D.Y. Taylor

dont forget to rate my answer :) 

 

Answer 2

First, you can use the 2 points to find the slope:

 

slope = (change in y) / (change in x)

 

slope = (17 - 9) / (12 - 0) = 8/12 = 4/3

 

Now, you can use the slope and a point to find the equation of the line (using the point-slope formula):

 

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

(y - 9) = (4/3)(x - 0)

y - 9 = (4/3)x

y = (4/3) x + 9