From the given table we will use the two points (10, 4) and (15, 10) to find the slope of the line
The rule of the slope is

Let (x1, y1) = (10, 4) and (x2, y2) = (15, 10)

The form of the linear equation is

substitute the value of m

To find b substitute x by 10 and y by 4

Subtract 12 from both sides

The equation of the line best fit is

At x = 40, substitute x by 40

The expected number of games own is 40 games