Question 55178
write an equation in slope-intercept form for the line that satisfies each set of conditions.

PASSES THROUGH (1,-1),PARALLEL TO THE LINE THAT PASSES THROUGH (4,1) AND (2,-3)
:
In order to find the equation of a line we need a point and a slope (m).  We don't have a slope, but we can find one using the slope formula: {{{highlight(m=(y2-y1)/(x2-x1))}}}  using the two points that they gave us: (x1,y1)=(4,1) and (x2,y2)=(2,-3)
{{{m=(-3-1)/(2-4)}}}
{{{m=-4/-2}}}
{{{highlight(m=2)}}} Parallel lines have equal slopes. 
Now that we have a slope (m=2) and a point (x1,y1)=(1,-1), we can use the point-slope formula to find the equation of a line:  {{{highlight(y-y1=m(x-x1))}}}
{{{y-(-1)=2(x-1)}}}
{{{y+1=2x-2}}}  Slope intercept form is {{{highlight(y=mx+b)}}}, so solve for y.
{{{y+1-1=2x-2-1}}}
{{{highlight(y=2x-3)}}}
Happy Calculating!!!