Answer:
4
Step-by-step explanation:
1. if the mass of coffee worth $10 is 'x', then its worth is 10x, and the worth of the mixture is 5(x+20);
2. using the previous item it is possible to write the next equation:
5(x+20)=4*20+10*x; ⇒ x=4.
3. the required mass is 4 pounds.
 
        
             
        
        
        
Answer:
answer is first option

wherein, a = 1, b = -3, c = -5
 
        
                    
             
        
        
        
Answer:
 N=250
Step-by-step explanation:
  "twice as many nickels as dimes"     means    N =2D     [eq1]
  "collection of nickels and dimes is worth $25"    means
         5N + 10D = 2500      [eq2]
    (To avoid using decimal points, PLZ express everything in cents.)
 
Substitution   (substitute N from eq1 into eq2]:
      5(2D) + 10D = 2500
       10D + 10D = 2500
           20D = 2500
             D = 125
 
       N=2D         [eq1 again]
       N=2(125)
       N=250
 
Check:
   Is   5(250) + 10(125) = 2500   ?
         1250 +  1250 = 2500   ?
           2500 = 2500   ?yes
 
        
             
        
        
        
The correct unit for this triangle would be cm. Hope this helps!