There is no question. I can help you if you can repost the question with a picture.
Answer:
-1/2
Because, for every one square, the line goes <em>down </em>by 1/2.
Ok so 4*5=20
so the area is 20meters
now lets convert 200cm to m
= 200/100=2m
now 20m/2=10
so therefore, the gardener would need 10 bags of grass seeds
hope this helped :)
The mid-point is basically the average of the coordinates. So for the x coordinate do (1+(-7))/2=-3. and for y, do (-10+7)/2=-3/2
This gives you the midpoint as (-3,-3/2)