Question

Write the expression of the line that passes through (3,4) and (2,-1) in slope-intercept form

Answer 1

We find the slope :

M = 5

We plug one of our points in this equation to find the y-int :

y = 5x + b

I chose to plug in point (2,-1)

-1 = 5(2) + b
Multiple the 2 by 5
-1 = 10 + b
Subtract 10 from both sides
B = - 11

We finally write our equation which is

y = 5x -11

Answer 2

To solve this problem, first we must find the slope to write an equation in point slope form, and then we can simplify that equation to be in slope-intercept form.

Slope is equal to change in y/change in x = m = 4 - (-1) / 3 - 2 = 5 / 1 = 5

This means that the slope is 5. To write an equation in point-slope form, we need a point (I will use (3,4) but you could use the other point as well) and the slope to complete the form y = m(x - h) + k.

If we plug in the respective values, we get:

y = 5(x-3) + 4

Now, we must simplify to make this equation in the form y = mx + b (slope-intercept form).

y = 5x - 15 + 4
y = 5x - 11

Your final answer is y = 5x - 11.

Hope this helps!