Question

Find the equation (in slope-intercept form) of the line passing through the points with the given coordinates: (1,2), (3,-1)

Answer 1

To find an equation, we must:
1) First find the slope
2) Use the equation y-y1 = m (x-x1)
3) Put it all together

To find the slope of the given points, we use:
y2-y1
-----
x2-x1

The given points are:
(1,2) : (x1,y1)
(3,-1) : (x2,y2)

Now plug it in the equation above:
y2 - y1 -1 - 2 -3
------ = ------ = --- = 'm'
x2-x1 3 - 1 2

SECOND STEP is to find to conclude to an equation using:
(y-y1) = m (x-x1)

Choose any one of those given points:
In my case, lets choose (1,2) as (x1,y1)

Now PLUG IN;
y - y1 = m (x - x1)
y - 2 = -3/2 (x - 2)
y - 2 = -3/2x + 6/2
y - 2 = -3/2x + 3
y = -3/2x + 5 (Final Answer)

Answer 2

I'd appreciate a 'Good Answer' :-) Danke

Answer 3

Okay, I got the slope part, but how did you figure the second half?

Answer 4

We first choose any one of the given points. In this case, I choose (1,2) to substitute in as (x1,y1) in the equation:
(y-y1) = m (x-x1)