SOLUTION: Write the equation of the line that passes through the points (3,7) and (-1,2) in: (a)Point-slope form (b)Slope-intercept form

Algebra ->  Graphs -> SOLUTION: Write the equation of the line that passes through the points (3,7) and (-1,2) in: (a)Point-slope form (b)Slope-intercept form       Log On


   

Question 1091666: Write the equation of the line that passes through the points (3,7) and (-1,2) in:
(a)Point-slope form
(b)Slope-intercept form

Found 2 solutions by Alan3354, josmiceli:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Write the equation of the line that passes through the points (3,7) and (-1,2)
==============
Step 1, find the slope.
Slope, m = diffy/diffx
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Step 2, use
y - y1 = m*(x-x1) where (x1,y1) is either point.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(a)
Use the general point-slope formula
+%28+y+-2+%29+%2F+%28+x+-%28-1%29+%29+=+%28+7+-+2+%29+%2F+%28+3+-%28-1%29+%29+
+%28+y+-+2+%29+%2F+%28+x+%2B+1+%29+=+5%2F4+
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(b)
Multiply both sides by +4%2A%28+x+%2B+1+%29+
+4%2A%28+y+-+2+%29+=+5%2A%28+x+%2B+1+%29+
+4y+-+8+=+5x+%2B+5+
+4y+=+5x+%2B+13+
+y+=+%285%2F4%29%2Ax+%2B+13%2F4+
-------------------------
Check:
Does the line go through (-1.,2) ?
+2+=+%285%2F4%29%2A%28-1%29+%2B+13%2F4+
+2+=+-5%2F4+%2B+13%2F4+
+2+=+8%2F4+
+2+=+2+
OK -you can check other point