SOLUTION: Would someone please explain step by step for me please, so I can see how to set up problem. Thanks Write the equation of the line with x-intercept (12,0)and y-intercept (0,4).

Algebra ->  Graphs -> SOLUTION: Would someone please explain step by step for me please, so I can see how to set up problem. Thanks Write the equation of the line with x-intercept (12,0)and y-intercept (0,4).      Log On


   

Question 81765: Would someone please explain step by step for me please, so I can see how to set up problem. Thanks
Write the equation of the line with x-intercept (12,0)and y-intercept (0,4).
Found 2 solutions by rapaljer, Edwin McCravy:
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
The equation of a line can be written in slope-intercept form, y=mx+b, where "m" is the slope and "b" is the y-intercept of (0,4). Since you are given the y-intercept, all you need is the slope, which is m=%28RISE%29%2F%28RUN%29+.

In this case, m=+%284-0%29%2F%280-12%29+=4%2F-12=-1%2F3.

The equation of the line is therefore: y=%28-1%2F3%29x%2B4.

R^2 at SCC

Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
Would someone please explain step by step for me please, so I can see how to set up problem. Thanks
Write the equation of the line with x-intercept (12,0)and y-intercept (0,4).
1. (12, 0) and (0,4) 


We first plot those two points and draw a line 
through them to find out if it is vertical or
not. The equations of all lines can be placed
in slope-intercept form except the equations
for vertical lines. This is the graph we get:

graph%28+300%2C+123%2C+-2%2C+15%2C+-1%2C6%2C++-x%2F3+%2B+4%29

We see that it is not vertical. So we can proceed
as usual:

We are to find an equation of the line containing 
the points (12,0) and (0,4)

Use the slope formula:

     y2 - y1
m = —————————
     x2 - x1

where (x1, y1) = (12,0) and (x2, y2) = (0,4)

     (4) - (0)      4      -1
m = ——————————— = ————— = ———— = -1%2F3
    (0) - (12)     -12      3 

Now substitute in the point slope formula:

   y - y1 = m(x - x1)

   y - 0 = -1%2F3(x - (12) )

      y  = -1%2F3(x - 12)

       y = -1%2F3x + 4

That's the equation in the slope-intercept
form because we can compare it with

       y = mx + b

and see that its slope m is -1%2F3 and its
y-intercept (0,b) is the point (0,4)
  
Edwin