Answer:
u can download the gauthmath app it's very helpful i PROMISE :)
 
        
                    
             
        
        
        
This is a mixture problem.
Let the 9 karat gold to be mixed be x. The 18 karat would weight (200 - x). Since the total = 200g.
mass1 * karat1 + mass2*karat = total mass * total carat
Let mass1 be x g.          mass 2 would be = (200 -x)
karat 1 = 9                    karat 2 = 18  
Total mass = 200g.
Total karat = 14.
9*x  + 18*(200 -x) = 14*200
9x + 18*200 - 18*x = 14*200
18*200 + 9x - 18x = 14*200
3600 - 9x = 2800
3600 - 2800 = 9x
800 = 9x
9x = 800
x = 800/9
x ≈ 88.89
Therefore 88.89 grams of 9 karat gold must be mixed.
        
             
        
        
        
Answer:
the admininstrative assistant can type 70 word in a minute i think
Step-by-step explanation:
 
        
             
        
        
        
Answer:

Step-by-step explanation:
We are given that Ben has a cell phone plan that provides 200 free minutes each month for a flat rate of $39.
We are also told that For any minutes over 200, Ben is charged $0.35 per minute. 
let x  be the minutes used each month
So, if 
So, coat will be $39
If 
So, Ben is charged $0.35 per minute
So, when 
So, charge = 
So, the piecewise functions accurately represents charges based on Ben's cell phone :
