Answer:
0,4.2
Step-by-step explanation:
 
        
             
        
        
        
Answer:
Barney 145 3 Days 310 Miles
Mary   250 5 Days 600 Miles
A)  3 D + 310 M = 145
B) 5 D + 600 M = 250
Multiplying A) by -5/3
A) -5 D - 516.6666M = -241.66666666
B) 5D + 600M = 250
Adding A) and B)
83.3333 M = 8.3333333333
M = .10 per mile
3 D = 114
Daily Rate = 38 dollars per day
Step-by-step explanation:
 
        
             
        
        
        
Answer: The number of $12 tickets and $15 sold are 120 and 180 respectively.
Step-by-step explanation:
The given equation is:
12x + 15y = 4140             .....(1)
Where,
x stands for $12 tickets and y stands for $15 tickets
According to the question:
x + y = 300           ....(2)
Now solving equation 1 and 2.
From equation 2:
x = 300 - y
Now putting this expression in equation 1.
12x + 15y = 4140
12(300 - y) + 15y = 4140
3600 - 12y + 15y = 4140
3600 + 3y = 4140
3y = 4140 - 3600
3y = 540
y = 180
And,
x = 300 - y = 300 - 180 = 120
The number of $12 tickets sold = x = 120
The number of $15 tickets sold = y = 180
Thus, the number of $12 tickets and $15 sold are 120 and 180 respectively.
  
        
             
        
        
        
Answer:
(1) 2π - x² = 0 (2) x = 2.5 cm (3) perimeter = 10 cm
Step-by-step explanation:
(1)The area of the circular coin without the inner square removed is πr² where r = 3 cm is the radius of the coin. So, the area of the coin without the inner square removed is πr² = π(3 cm)² = 9π cm²
The area of the square of x sides removed from its center is x².
The area A of the each face of the coin is thus A = 9π - x²
Since the area of each face of the coin A = 7π cm²,
then
7π = 9π - x²
9π - 7π - x² = 0
2π - x² = 0
(2) Solve the equation 2π - x² = 0
2π - x² = 0 
x² = 2π 
x = ±√(2π) 
x = ± 2.51 cm
Since x cannot be negative, we take the positive answer.
So, x = 2.51 cm 
≅ 2.5 cm 
(3) Find the perimeter of the square
The perimeter of the square, p is given by p = 4x
p = 4 × 2.51 cm
 = 10.04 cm 
≅ 10 cm