Question 24897
1) Write the equation of the line passing through the points: (-1, 3) and (4, -2)

First, find the slope m, using the slope formula:

{{{m = (y2 - y1)/(x2 - x1)}}} where: (x1, y1) = (-1, 3) and (x2, y2) = (4, -2)
{{{m = (-2 - 3)/(4 - (-1))}}}
{{{m = -5/5}}}
{{{m = -1}}}

Now you can write, in slope-intercept form: {{{y = mx + b}}}:

{{{y = (-1)x + b}}} Now you need to find the value of b, the y-intercept. 
You do this by substituting the x- and y-values from either one of the two given points and solving for b. Let's use the second point (4, -2):
{{{-2 = (-1)(4) + b}}} Simplify and solve for b.
{{{-2 = -4 + b}}} Add 4 to both sides of the equation.
{{{2 = b}}} Now you have b you can write the final equation in slope-intercept form:

{{{y = -x + 2}}}

Here's the graph of this line:
{{{graph(300,200,-5,5,-5,5,-x+2)}}}

You can follow this procedure on the second problem.