A. Julia does not know how many tickets she is going to by. She knows that each ticket costs $8.
        
             
        
        
        
Answer:
Radius length: √5
Standard Form (Equation): (x + 4)^2 + y^2 = 5
Step-by-step explanation:
First we will determine the radius;
Center: (-4, 0)
Point on Circumference: (-2, 1)
d = √(-2 - (-4))^2 + (1 - 0)^2 = √(2)^2 + (1)^2
= √4 + 1 = √5
Therefore the radius is of length √5
Now the equation of a circle is in the form ((x - h)^2 + (y - k)^2) = r^2. The center is in the form (h,k) and r is the radius. Given this our equation would be (x - (-4))^2 + (y - 0)^2 = (√5)^2, or [simplified] (x + 4)^2 + y^2 = 5.
 
        
                    
             
        
        
        
The two linear equations in two variable is:
12 x + 3 y = 40
7 x - 4 y = 38
(a) For a system of equations in two Variable 
a x + by = c
p x + q y = r
It will have unique solution , when

As, you can see  that in the two equation Provided above 
 
So, we can say the system of equation given here has unique solution.
(b). If point (2.5, -3.4) satisfies both the equations, then it will be solution of the system of equation, otherwise not. 
1. 12 x+3 y=40
2. 7 x-4 y=38
Substituting , x= 2.5 , and y= -3.4 in equation (1) and (2),
L.H.S of Equation (1)= 1 2 × 2.5 + 3 × (-3.4)
                              = 30 -10.20
                                = 19.80≠ R.H.S that is 40.
Similarly, L H S of equation (2)= 7 × (2.5) - 4 × (-3.4)
                                                   = 17.5 +13.6
                                                   = 31.1≠R HS that is 38
So, you can Write with 100 % confidence that point (2.5, -3.4) is not a solution of  this system of the equation. 
 
        
             
        
        
        
Answer:
Option 2 and 5 are correct.
Step-by-step explanation:
We need to tell which one of them is quadratic function.
Option 1 is exponential decay so, it is not quadratic.
Option 2 is quadratic because the diver will take the parabolic shape when jumps.
Option 3 is not quadratic.Option 4 is not quadratic it is linear.
Option 4 is again exponential not quadratic.
Option 5 is quadratic because it takes the parabolic shape again.