Equation of a Line with 2 Points.
23 Sep 09
How to find the equation of a line?
A) First lets find the slope using the equation:
slope=m=(y2-y1)/(x2-x1)
m=[6-(-1)]/[4-(-1]=(6+1)/(4+1)=7/5
Now lets find the equation of the line using the formula:
y=mx+b and the coordinates (-1,-1).
We know the slope is 7/5 and x=-1, y=-1 from (-1,-1).
y=mx+b
-1=(7/5)(-1)+b
-1=-(7/5)+b
-1+7/5=b
-5/5+7/5=b
2/5=b
Therefore: y=(7/5)x+2/5
B) or another way to solve this question:
We can use the following equation:
(y-y1)=m(x-x1)
from above we calculated m=7/5
(y-(-1))=(7/5)(x-(-1))
(y+1)=(7/5)(x+1)
y+1=(7/5)x+(7/5)
y=(7/5)x+(7/5)-1
y=(7/5)x+2/5
A) First lets find the slope using the equation:
slope=m=(y2-y1)/(x2-x1)
m=[6-(-1)]/[4-(-1]=(6+1)/(4+1)=7/5
Now lets find the equation of the line using the formula:
y=mx+b and the coordinates (-1,-1).
We know the slope is 7/5 and x=-1, y=-1 from (-1,-1).
y=mx+b
-1=(7/5)(-1)+b
-1=-(7/5)+b
-1+7/5=b
-5/5+7/5=b
2/5=b
Therefore: y=(7/5)x+2/5
B) or another way to solve this question:
We can use the following equation:
(y-y1)=m(x-x1)
from above we calculated m=7/5
(y-(-1))=(7/5)(x-(-1))
(y+1)=(7/5)(x+1)
y+1=(7/5)x+(7/5)
y=(7/5)x+(7/5)-1
y=(7/5)x+2/5