The slope Intercept form is :
\(Y = mx + b \)
where m is the slope of the line
b is the point of intersection with the Y axis .
for the point ( 6,8) and m = 1/2
\(8 = \frac{1}{2}*6 + b \)
\(8 = 3 + b \)
\(b = 8 - 3 \)
\(b = 5 \)
\(Y = \frac{1}{2}x + 5 \)