Yes, you need to find the equation of the line (y=mx+c). The first step is to calculate the gradient. You can do this by dividing the change in y (2) by the change in x (1). This gives you a gradient of 2. You now have y=2x+c. To find c (the y intercept) look at the point where the line crosses the y axis (in this graph it is 1).
You have now found that the line equation is : y=2x+1