Question

Write an equation in slope-intercept form for the line shown.
The equation in slope-intercept form is _______ .

Answer 1

To write the equation in slope-intercept form

  ⇒ must know what is the slope-intercept form

       ⇒ $y = mx + b$

• m: the value of the slope
• b: the value of the y-intercept

Let's find the slope first:

   ⇒ must know the slope's formula

       ⇒ $\frac{y2-y1}{x2-x1}$

• (x1, y1) --> one point on the line
• (x2, y2) --> another point on the line that is not (x1, y1)

1. Let's choose (0,1) and (-3,0)
2. Now let's find the slope

          ⇒ $\frac{0-1}{-3-0}=\frac{-1}{-3} =\frac{1}{3}$

Now let's find the y-intercept

  ⇒ which occurs where the x-value of the coordinate is 0

    ⇒ that point is (0,1)

       ⇒ thus b = 1

Now let's set up the equation in slope-intercept form

     $y = \frac{1}{3} x+1$   <-- Answer

Hope that helps!