Answer:
x=5
Step-by-step explanation:
We can write ratios to help us solve
4x            12 +3
---------- = ------------
3x+1                 12
Using cross products
4x*12 = (3x+1) * (15)
48x = 45x +15
Subtract 45x from each side
3x =15
Divide by 3
3x/3 =15/3
x=5
 
        
             
        
        
        
The correct answer is A. 2cm
18      2cm
---- = ----
45      5cm
hope this helps
        
             
        
        
        
Answer:
the second one
Step-by-step explanation:
Its measuring by miles per hour
 
        
                    
             
        
        
        
Answer:
24
Step-by-step explanation:
3.2x5 x1.5=24 
Hope this helps :)
 
        
                    
             
        
        
        
Answer:
Step-by-step explanation:
concentration = amount of salt/solution
A) Initial concentration= 90/1000 = 0.09
Q = quantity of salt 
Q(0) = 90 kg
Inflow rate = 8 l/min
Outflow rate = 8 l/min
Solution = 1000 L at any time t.
Salt inflow = 0.045 * 8 per minute
= 0.36 kg per minute
This is mixed and drains from the tank.
Outflow = 
Thus rate of change of salt 
Q'(t) = inflow - outflow = 
Separate the variables and integrate

Use the fact that Q(0) = 90
90 = 360-A
A = 270
So 

B) Q(t) = 360-270e^-0.004  = 91.07784
C) When t approaches infinity, we get
Q(t) tends to 360
So concentration =360/1000 = 0.36