Use two points from the graph to check if they are constant. In this case let’s use (0,50) & (2,58)
To find slope you have to do the following.
y2-y1 / x2-x1
Plug in the values, 58-50/2-0
This gives you 4.
When you use two other points, in this case (10,90) (20,130) you get a slope of 4.
This means the slope is 4.
We are trying to get an equation of y=mx+b.
We have slope already which is 4. So now we plug in y=4x + b
Now we need to find b. There is an equation to solve for b. Which is b=y1-m(x1)
But b is the y-intercept so there is already a B which is 50
So the table IS a linear equation and the equation is y=4x+50.
