The 2 angles at a vertex are supplementary (one interior and one exterior) the exterior angle is = the the sum of the 2 remote interior angles..
        
             
        
        
        
Use formula: an = a1 * r^(n-1)
a1 = 2, r = -2 
a12 = 2 * -2^(12-1)
a12 = 2 * -2^11
a12 = 2 * -2048
a12 = -4096
Solution: -4096
        
                    
             
        
        
        
The answer is 5.
the numbers are 5 & -2
        
             
        
        
        
<span>In order to determine the value of the numbers, we can set up algebraic equations to solve. For this case, we need to set up two equations since we have two unknown numbers. We do as follows:
 let x = first number and y = second number
 From the problem statement, we set up equations. 
 Equation 1 - the numbers have a difference of 0.7
 x - y = 0.7
 Equation 2 - the numbers have a sum of 1
 x + y = 1
 Solving for x and y via substitution method,
 x - y = 0.7
(1-y) - y = 0.7
1 - 2y = 0.7
-2y = 0.7 - 1 = -0.3
y = 0.15 or 3/20
 x - 0.15 = 0.7
x = 0.85 or 17/20
 Thus, the two numbers are 0.15 and 0.85.</span>
        
             
        
        
        
Answer:
The integer that represents the change in the temperature each week = 5
The temperature of the weather drops 5°F each week
Step-by-step explanation:
The given parameters regarding the weather are;
The range over which the temperature dropped = 20°F
The duration over which the temperature dropped = 4 weeks
The rate at which the weather dropped each week = The same amount (constant rate)
Therefore, we have;
For a constant rate of change, the rate of change of the temperature of the weather, m, is given as follows;
m = (The change in the temperature)/(The duration of the change)
m = 20°F/(4 weeks) = 5°F/week
The integer that represents the change in the temperature each week = 5