We know that the y-intercept is (0, 3), since that's the point on y-axis. Now that we know this, we know the value of 'b'
y = mx + b y = mx + 3
Now all we have to do is solve for m. Recall that 'm' represents the slope, and that the equation to find the slope is rise/run. Essentially, you have to find two points and figure out the number of units you have to travel through the x-axis and y-axis.
In this question, they've already gave us two points (The black dots) that we can use to find the slope. In order to get the dot on the to the dot on the bottom, we have to go down 5 times. This means that the rise is -5.
Now all we have to do is go right until we reach the point. In this question, you have to go the right 4 times, making the run 4.
And so we've found the slope: -5/4. Since the slope is 'm,' we can now complete our equation. y = mx + 3 y = -5/4x + 3
Let me know if you need me to explain anything in more depth :)) -T.B.
