Making an Equation from a Table (Option 2) By: Mrs. Waters

Option 2 is finding the slope (or coefficient) using rise over run. To do this, we will be finding the change in the y values and the change in the x values.

Here is our table. Let’s start with the slope or coefficient. XY

When we rise? What value changes? The x value stays the same and the y value changes

When we run? What value changes? The y value stays the same and the x value changes

Rise = Change in y values So, what does that mean for rise over run? Run = Change in x values

So, let’s find our coefficient (slope) by doing rise (change in y’s) over run (change in x’s) XY What is our change in y’s (rise)? +2 Our run is 2 What is our change in x’s (run)? +4 Our rise is 4

Rise = Change in y values = 4 So, our rise was 4 and our run was 4 Run = Change in x values = 2 So, our coefficient (or slope) = 2 =2

So, now we know our coefficient (slope) is 2. Let’s put it in the equation. But does this equation work for our table? Let’s find out by SUBSTITUTING! YAY! y = 2x

Let’s use x=0 to substitute. So…. Does y=0 when x=0? y = 2x y = 2(0) XY

XY So, what do we need to make the equation work? + (-4) y = 2x

So, our equation is…. Now it’s your turn….. y = 2x + (-4)

Find the equation for the given table. Click to the next slide to check your answer. XY

XY Another? Maybe with a graph?

Create an equation from the Graph Find the points on the graph to make a table. Click to the next slide to check your answer.

XY