f(x) =1/2x +5

This equation in it the slope intercept form.

Y = mX + b where m is the slope and b is the y intercept.

Put a point on the graph at the Y intercept (0, 5)

The slope, m = (change in y) / (change in X) in this case 1/2

From the drqwn point move up 1 and right 2 and place a second point. Draw a line between the 2 points.