Answer:
The 21st term is 137.
Step-by-step explanation:
Arithmetic progression:
In an arithmetic progression the difference between consecutive terms is always the same, and its called common difference.
The nth term is given by:

In which  is the first term and d is the common difference.
 is the first term and d is the common difference.
The first two terms are -3, 4. 
This means that 
So


The 21st term is

The 21st term is 137.
 
        
             
        
        
        
Answer:
PQ and QR are congruent.
Step-by-step explanation:
The length of PQ = sqrt [(2 - -1)^2 + (-1 - 3)^2]
= sqrt 25
= 5 units.
QR =  sqrt [(5-2)^2 + (3 - -1)^2) ]
= sqrt 25
= 5 units.
PR =  sqrt [ ( 3-3^2 + (5- -1)^2]
= sqrt 36
= 6 units.
 
        
             
        
        
        
 Any line can be expressed in the form y=mx+b where m is the slope and b is y intercept.
Two lines can either be parallel ,overlap or meet at one point .Let us look at different cases :
1)When two lines are parallel they do not intersect at any point and hence the system of equations have no solution.
2) When two lines overlap each other then the two lines touch each other at infinite number of points and we say the system of equations have infinite solutions.
3) When two lines intersect each other at one point we say the system of equation has one solution.
Part A:
The given lines are intersecting at one point so we have one solution.
Part B:
The point of intersection is the solution to the system of equations .In the graph the point of intersection of the lines is (4,4)
Solution is (4,4)
 
        
                    
             
        
        
        
Answer:
3.14     (or pi )  feet  
Step-by-step explanation:
Entire circle circumference  = pi *d  = 8 pi    feet
45 degrees is a fraction of the entire 360 degrees of the circle
    45 / 360  *  8 pi = pi =  3.14 ft