A]
D=R×t
d=5.8r
d2=5.1(r+7)
0.7r=35.7
r=51 mi/hr
thus the average speed on the outbound trip would be:
51+7=58 mi/hr
b] 
let speed of fishing boat=x km/h
speed of cruise ship=(x+12.5) km/h
distance traveled by fishing boat=11.5×x=11.5x km
distance traveled by cruise ship=(x+12.5)×11=(11x+137.5) km
Total distance covered by the ships:
11.5x+11x+137.5=322
22.5x=322-137.5
22.5x=184.5
thus
x=184.5/22.5
x=8.2 km/h
The speed of fishing boat is 8.2 km/hr
        
                    
             
        
        
        
In any trapezoid, the area is given by

where B and b are the two bases, and h is the height. You're given all these elements already, so you only need to plug the values in:

 
        
             
        
        
        
Answer:
Terrance is 25.5
Step-by-step explanation:
 
        
                    
             
        
        
        
Answer:
10.63
Step-by-step explanation:
The distance between two points is sqrt((difference between y-values)^2 + (difference between x-values)^2) -->
sqrt(8^2 + 7^2) =
sqrt(64 + 49) =
sqrt( 113) =
10.630145 -->
10.63