7. (6/8)
8. (2/10)
10. (4/12)
11. (4/8)
13. (10/12)
14. (6/12)
16. (9/12)
17. (5/10)
Ac - 5ad - 5bc + 25bd = a(c - 5d) - 5b(c - 5d) = (c - 5d)(a - 5b)
The slope of the line is 2.
<u>Step-by-step explanation:</u>
The given points are (5,-3) , (6,-1) , (7,1) , (8,3).
To find the slope of the line that contain these points is calculated by the slope formula.
Slope = 
Take any two points from the given set of points.
Let,
(x1,y1) = (5,-3)
(x2,y2) = (6,-1)
Slope =
⇒ 2
Therefore, the slope of the line is 2.
Similarly, the slope of the line can be known by using any two points on the line in the slope formula.
19. $30,681.82
20. Find surface area for this one
21. Use geometry