Answer: y = 3x + 60
<u>Step-by-step explanation:</u>
Set up two equations and solve the system:
  270 = 70x + b
- <u>(150 = 30x + b)</u>
   120 = 40x
     3   =  x
Input "x" into one of the equations and solve for "b":
150 = 30x + b
150 = 30(3) + b
150 = 90 + b
60 = b
Equation: y = 3x + 60
This means that there is a flat fee of $60 plus a rate of $3 per student
 
        
             
        
        
        
1 file + 3 pens = $32.85     --------------- (1)
2 files + 8 pens = $83.50   ----------------(2)
(1) x 2 :
2 files + 6 pens = $65.70   ----------------(1a)
(2) - (1a) :
2 pens = $17.80
1 pen = $8.90
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Answer: One pen costs $8.90.
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Answer:
-5/6
Step-by-step explanation:
-1 2/3=-5/3
-5/3+5/6=-10/6+5/6=-5/6
 
        
                    
             
        
        
        
F(x) = [x] - 2 + 8
[x] is the notation for 'greatest integer function'
f(-1.8) = [-1.8] - 2 + 8 = -2 -2 + 8 = 4
The answer is 4