Question 65122
find the equation of a line for this points (-1,3) and (3,-4)
In order to find the equation of a line, you need a point and a slope.
Youe can find the slope between two points using the slope formula:
{{{highlight(m=(y2-y1)/(x2-x1))}}}, m=slope, (x1,y1) and (x2,y1) are two given points.
(x1,y1)=(-1,3) and (x2,y2)=(3,-4)
{{{m=(-4-3)/(3-(-1))}}}
{{{m=-7/4}}}
You can find the equation with a point and a slope using the point-slope formula:  {{{highlight(y-y1=m(x-x1))}}}, m=slope and (x1,y1)=given point.
The slope, m=-7/4, (x1,y1) can be either point, to avoid confusion, I'm going with: (x1,y1)=(-1,3)
{{{y-3=(-7/4)(x-(-1))}}}
{{{y-3=(-7/4)(x+1)}}}
{{{4(y-3)=4(-7/4)(x+1)}}}
{{{4y-12=-7(x+1)}}}
{{{4y-12=-7x-7}}}
{{{4y-12+12=-7x-7+12}}}
{{{4y=-7x+5}}}
{{{7x+4y=7x-7x+5}}}
{{{highlight(7x+4y=5)}}}  This is the equation in standard form.
Happy Calculating!!!