Expert: Pawan Musale - 9/21/2009

Question
I'm in 10th grade I dont understand this queston it states:
Write an equation of the line that passes through the given points which are (3,4), (0,3)
I do not know what formula to use.

Answer
Chasya,

Two points given are:  
(3,4) ---> (x1, y1)
(0,3) ---> (x2, y2)

First find slope (m) of the line which is given by formula:

m = (y2-y1)/(x2-x1)

Putting the above values,

m = (3-4)/(0-3) = -1/-3 = 1/3 ------------------------ #1

When we know slope and at least one point of line, then line equation can be found using slope-point equation:

y-y1 = m(x-x1)

Putting the values of first point given,

y - 4 = (1/3)(x-3)
3(y-4) = x - 3
3y - 12 = x -  3
x - 3y = -9 ------------------ #2

So x - 3y = -9 is the equation of given line.

Note: This can be verified by putting co-ordinates of other given point.

I hope this helps you.

Let me know if you need additional information.

Kindly rate this answer.

Regards,
Pawan