In order to determine the equation of the line, use the following general expression for the equation:
y - yo = m(x - xo)
where m is the slope of the line and (xo,yo) is any point of the line.
To calculate m use the following espression:
m = (y2 - y1)/(x2 - x1)
where, for this case (x1,y1) = (2,5) and (x2,y2) = (8,2):
m = (2 - 5)/(8 - 2) = -3/(6)
m = -1/2
next, replace m and (xo,yo) = (2,5) into the general expression, and solve for y, as follow:
y - 5 = -1/2(x - 2)
y - 5 = -1/2x + 1
y = -1/2 x + 6 this is the euqation of the line