9) x= -6 
10) x= 3/2
11) x= -4,0,5 
12) no solution
        
             
        
        
        
Answer:
first do: 
60mph * 4 hours= 240mi
Let D = the distance the passenger train has to  
travel to catch the freight train
Start a stopwatch when the passenger train leaves
Let t = the time on the stopwatch when they meet
Equation for freight train:
d-240=60t
Equation for passenger train: 
d=100t
all together:
100t-240=60t
we can do 100t-60t because they both have (t)= 40t
40t=240 *now divide 240 by 40= 6
THEN do:
D= 100mph x 6= 600mi 
They will meet 600 mi from the station
to check:
d-240=60t x 6
600-240= 360
60 x 6= 360
360=360
 
        
             
        
        
        
Step-by-step explanation:
yes its ans is (3,3) fast you have see in x axis then y axis .so according to this we write 3 which lies in x- axis and then another 3 which lies in y-axis.
 
        
             
        
        
        
Answer:
14,628,440,464
Step-by-step explanation:
Perform simple addition.
Glad I was able to help!!
 
        
                    
             
        
        
        
Answer:
L(f(t)) = 
Step-by-step explanation:
f ( t ) = 10 cos ( 12t + 60°) u(t)
attached below is a detailed solution of the given problem
L(f(t)) = 