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).

1. (12, 0) and (0,4) <BR>
<PRE><font size = 5><b>
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( 300, 123, -2, 15, -1,6,  -x/3 + 4)}}}

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:

     y<sub>2</sub> - y<sub>1</sub>
m = —————————
     x<sub>2</sub> - x<sub>1</sub>

where (x<sub>1</sub>, y<sub>1</sub>) = (12,0) and (x<sub>2</sub>, y<sub>2</sub>) = (0,4)

     (4) - (0)      4      -1
m = ——————————— = ————— = ———— = {{{-1/3}}}
    (0) - (12)     -12      3 

Now substitute in the point slope formula:

   y - y<sub>1</sub> = m(x - x<sub>1</sub>)

   y - 0 = {{{-1/3}}}(x - (12) )

      y  = {{{-1/3}}}(x - 12)

       y = {{{-1/3}}}x + 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 {{{-1/3}}} and its
y-intercept (0,b) is the point (0,4)
  
Edwin</PRE></b></font>