Question 55022
Find the slope of a line that passes through (1,7) and (3,3). Please start with showing me the general formula for slope of a line.
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Hi DB
To find the equation of a line we need a point and a slope.  We have a point, but no slope.  We can find a slope (m)if we're given 2 points by using the slope formula: {{{highlight(m=(y2-y1)/(x2-x1))}}}
Our (x1,y1)=(1,7) and (x2,y2)=(3,3)
{{{m=(3-7)/(3-1)}}}
{{{m=-4/2}}}
{{{highlight(m=-2)}}}
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I should have stopped here.  You only asked for the slope.  I got carried away and gave you the equation of a line.  You'll be doing that soon if you aren't already, so I'll leave it here.
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Now we have a point (x1,y1)=(1,7) and a slope m=-2, so we can find the equation of the line using the point slope formula: {{{highlight(y-y1=m(x-x1))}}}.
{{{y-7=-2(x-1)}}}
{{{y-7=-2x+2}}}
{{{y-7+7=-2x+2+7}}}
{{{y=-2x+9}}}<----slope intercept form {{{highlight(y=mx+b)}}}
{{{2x+y=2x-2x+9}}}
{{{2x+y=9}}} <---Standard Form {{{highlight(Ax+By=C)}}}.
Happy Calculating!!!
funmath