SOLUTION: please help me solve this. write an equation of a line given (x1,y1)=(12,7) and (x2,y2)=(-4,5)

Algebra ->  Linear-equations -> SOLUTION: please help me solve this. write an equation of a line given (x1,y1)=(12,7) and (x2,y2)=(-4,5)       Log On


   

Question 6348: please help me solve this.
write an equation of a line given (x1,y1)=(12,7) and (x2,y2)=(-4,5)

Found 2 solutions by AnlytcPhil, ichudov:
Answer by AnlytcPhil(1807) About Me  (Show Source):
You can put this solution on YOUR website!
write an equation of a line given (x1,y1)=(12,7) and (x2,y2)=(-4,5)
m+=+%28y2-y1%29%2F%28x2-x1%29
m+=+%285-7%29%2F%28-4-12%29
m+=+%28-2%29%2F%28-16%29
m+=+1%2F8
Now use
y-y1+=+m%28x-x1%29
y-7+=+%281%2F8%29%28x-12%29
y-7+=+%281%2F8%29x-3%2F2
y+=+%281%2F8%29x-3%2F2+%2B+7
y+=+%281%2F8%29x-3%2F2+%2B+14%2F2
y+=+%281%2F8%29x%2B+11%2F2
That will do as a final answer if you only want the slope-intercept
form, or,
you can multiply through by 8 and get rid of fractions
8y+=+x+%2B+44
and to get it in standard form Ax + By = C
-x+%2B+8y+=+44
and since the standard form requires that A be positive,
we multiply thru by -1
x+-+8y+=+-44
Edwin

Answer by ichudov(507) About Me  (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: FIND EQUATION of straight line given 2 points
hahaWe are trying to find equation of form y=ax+b, where a is slope, and b is intercept, which passes through points (x1, y1) = (12, 7) and (x2, y2) = (-4, 5).
Slope a is a+=+%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29+=+%285-7%29%2F%28-4-12%29+=+0.125.
Intercept is found from equation a%2Ax%5B1%5D%2Bb+=+y%5B1%5D, or 0.125%2A12+%2Bb+=+5.5. From that,
intercept b is b=y%5B1%5D-a%2Ax%5B1%5D, or b=7-0.125%2A12+=+5.5.

y=(0.125)x + (5.5)

Your graph: