2. 24-7p=10
-7p=-14
p=2
3. x+(x+1)+(x+2)=72
3x+3=72
3x=69
x=23
4. x+(x+2)+(x+4)=48
3x+6=48
3x=42
x=14
7. 40-2x=8
-2x=-32
x=16
8. 1/2x+4=12
1/2x=8
x=16
Slope = (y2-y1)/(x2-x1) = (8-2)/(3-1) = 6/2 = 3. So the answer is c.

Not the prettiest but you can simplify