SOLUTION: HOW CAN I FIND THE EQUATION OF THE LINE PASSING THROUGH THE GIVEN POINTS? AFTER YOU FIND THE EQUATION OF THE LINE PASSING THROUGH THE GIVEN POINTS HOW DO YOU FIND THE Y-INTERCEPT?

Algebra ->  Linear-equations -> SOLUTION: HOW CAN I FIND THE EQUATION OF THE LINE PASSING THROUGH THE GIVEN POINTS? AFTER YOU FIND THE EQUATION OF THE LINE PASSING THROUGH THE GIVEN POINTS HOW DO YOU FIND THE Y-INTERCEPT?      Log On


   

Question 17723: HOW CAN I FIND THE EQUATION OF THE LINE PASSING THROUGH THE GIVEN POINTS?
AFTER YOU FIND THE EQUATION OF THE LINE PASSING THROUGH THE GIVEN POINTS HOW DO YOU FIND THE Y-INTERCEPT?
Answer by xcentaur(357) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose you have two points P(a,b) and Q(c,d)
Let the line passing through P and Q have a slope 'm'
Then +m=%28d-b%29%2F%28c-a%29
or [difference in y-coordinates/difference of x-coordinates]


Now take any one of the two points,say P(a,b)
We have the slope m
Taking slope-point form we get
y-b=m(x-a)


Now we have the equation,to find the yintercept put x=0
y-b=m(x-a)
y-b=m(0-a)
y-b=-am


To make it clear,take an example
There are two points A(1,5) B(4,7). Find the slope,equation and y-intercept.
A(1,5) B(4,7)
slope m=(7-5)/(4-1)
m=2/3
Equation of the line taking point A:
(y-5)=m(x-1)
y-5=2/3(x-1)
3(y-5)=2(x-1)
3y-15=2x-2
3y=2x-2+15
3y=2x+13
To find y-intercept,x=0
3y=2(0)+13
3y=15
y=5
therefore,Y-intercept=(0,5)


Hope this helps,
Prabhat