SOLUTION: Please, I need help! 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. Thanks, DB

Algebra ->  Linear-equations -> SOLUTION: Please, I need help! 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. Thanks, DB      Log On


   



Question 55022: Please, I need help!
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.
Thanks,
DB

Found 2 solutions by Earlsdon, funmath:
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
To find the slope, m, of a line that passes through the two given points, (x1, y1) and (x2, y2), use the formula:
m+=+%28y2-y1%29%2F%28x2-x1%29
In your problem, the given points are: (x1, y1) is (1, 7) and (x2, y2) is (3, 3).
If you now make the appropriate substitutions into the slope formula you will have found the slope of the line.
m+=+%283-7%29%2F%283-1%29 Simplify this to get:
m+=+%28-4%29%2F2
m+=+-2

Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
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.
:
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%28m=%28y2-y1%29%2F%28x2-x1%29%29
Our (x1,y1)=(1,7) and (x2,y2)=(3,3)
m=%283-7%29%2F%283-1%29
m=-4%2F2
highlight%28m=-2%29
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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.
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
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%28y-y1=m%28x-x1%29%29.
y-7=-2%28x-1%29
y-7=-2x%2B2
y-7%2B7=-2x%2B2%2B7
y=-2x%2B9<----slope intercept form highlight%28y=mx%2Bb%29
2x%2By=2x-2x%2B9
2x%2By=9 <---Standard Form highlight%28Ax%2BBy=C%29.
Happy Calculating!!!
funmath