From the average of the x coordinate and y coordinates.

(8+0)/2=4 and (11+5)/2=8. Thus, the point is (4,8).

Same as the slope of AB because it is part of the same line.b) the gradient of OM,

Thus, (11-5)/(0-8)=(-6)/(-8)=3/4

Use the distance formula,c) the lenght of the line AB,

(0-8)^2+(11-5)^2=8^2+6^2=64+36=100

But that is the square of the distance. Take the square root,

10

The y-intercept is 11 because you have (0,11) and x=0 at that point.d) the equation of the line AB

Thus, the equation is,

y=(3/4)x+11