A) c=18
0.5c^2 +13=94
subtract 13 from both sides
0.5c^2 = 81 
Square root of both sides to get c alone 
0.5c=9
double c to make it just c
c=18
B) x=8
(x-2)^2+1=37
Subtract one from each side
(x-2)^2=36
square root each side 
x-2=6
add the 2 over 
x=8
        
             
        
        
        
Answer:
The measure of the shortest side is 851 miles
Step-by-step explanation:
Let
x ----> the measure of the shortest side
y ---> the measure of the middle side
z ---> the measure of the longest side
we know that
The perimeter of triangle is equal to


so
 ----> equation A
 ----> equation A
the shortest side measures 71 mi less than the middle side
so
 ----> equation B
 ----> equation B
the longest side measures 372 mi more the the middle side
so
 ----> equation C
 ----> equation C
substitute equation B and equation C in equation A

solve for y

Find the value of x

therefore
The measure of the shortest side is 851 miles
 
        
             
        
        
        
Assume the number of trucks is x
number of cars is 5x
5x+x=30
6x=30
x=5
Julia saw 5 trucks