Answer:
x = -1  y = -1
Step-by-step explanation:
x + 3y = −4
x + 5y = −6
Multiply the first equation by -1
-x - 3y = 4
The add to the second equation to eliminate x
-x - 3y = 4
x + 5y = −6
--------------------
  2y = -2
Divide by 2
2y/2 = -2/2
y = -1
Now solve for x
x+3y = -4
x +3(-1) = -4
x -3 = -4
Add 3 to each side
x-3+3 = -4+3
x = -1
 
        
                    
             
        
        
        
Answer:
b. -3
Step-by-step explanation:
i hope this helps :)
 
        
             
        
        
        
Answer:
Approximately  (
 ( .) (Assume that the choices of the
.) (Assume that the choices of the  passengers are independent. Also assume that the probability that a passenger chooses a particular floor is the same for all
 passengers are independent. Also assume that the probability that a passenger chooses a particular floor is the same for all  floors.)
 floors.)
Step-by-step explanation:
If there is no requirement that no two passengers exit at the same floor, each of these  passenger could choose from any one of the
 passenger could choose from any one of the  floors. There would be a total of
 floors. There would be a total of  unique ways for these
 unique ways for these  passengers to exit the elevator.
 passengers to exit the elevator.
Assume that no two passengers are allowed to exit at the same floor. 
The first passenger could choose from any of the  floors.
 floors. 
However, the second passenger would not be able to choose the same floor as the first passenger. Thus, the second passenger would have to choose from only  floors.
 floors.
Likewise, the third passenger would have to choose from only  floors.
 floors.
Thus, under the requirement that no two passenger could exit at the same floor, there would be only  unique ways for these two passengers to exit the elevator.
 unique ways for these two passengers to exit the elevator.
By the assumption that the choices of the passengers are independent and uniform across the  floors. Each of these
 floors. Each of these  combinations would be equally likely.
 combinations would be equally likely. 
Thus, the probability that the chosen combination satisfies the requirements (no two passengers exit at the same floor) would be:
 .
.
 
        
             
        
        
        
36 1/2 = 6
 Given: the exponential expression 
 
        
                    
             
        
        
        
Step-by-step explanation:
x^2 -2kx +7k -12 = 0
two equal roots -->Δ = b^2 -4ac = 4k^2 - 4(7k-12)=0 = 4(k^2 - 7k +12)=4(k-4)(k-3)=0
so k =3 and k =4