13) If T(n) = 2n-7, what is the 5th term?
n is the number of the term you are looking for. In this instance, n is equal to 5.
T(5) = 2(5) - 7
T(5) = 10 -7
T(5) = 3
The 5th term is 3.
17) inequality based on the line number.
Since the line does not extend in any direction outward. It means that the range should be within -3 and 3. 
Solid circle means that -3 is equivalent to x
hollow ciccle means that 3 is not x.
-3 <u><</u> x < 3
x = any number from -3 upto 2.
        
             
        
        
        
To solve this problem, we must set up a system of equations. In this case, let's let Maggie's age be represented by the variable m and her brother's age be represented by the variable b. We are told that the sum of their ages is 24, which gives us our first equation: m + b = 24. We can construct our next equation from the first sentence of given information: b = 2m - 3. This makes our system of equations:
m + b = 24
b = 2m - 3
To solve, we are going to substitute the value for b in terms of m given by the second equation into the first equation for the variable b.
m + b = 24
m + 2m - 3 = 24
To simplify, we must first combine the variable terms on the left side of the equation using addition.
3m - 3 = 24
Next, we should add 3 to both sides of the equation to get the variable term alone on the left side of the equation.
3m = 27
Finally, we should divide both sides by 3 in order to get the variable m alone.
m = 9
Therefore, Maggie is 9 years old (using the first equation and substituting in this value you can find that her brother is 15 years old).
Hope this helps!
 
        
                    
             
        
        
        
The answer is C), 834, 834.19, 834.2, 834.29
I know this is late, but I hope it was helpful!
 
        
             
        
        
        
Vbox-vspheres
vbox=, I assume we are dealing with l=w=h
so
v=lwh=12^3=1728
vsphere=(4/3)pir^3
r=3
vsphere=(4/3)pi3^3=4pi9=36pi
8 of them so 
8 times 36pi=288pi or about 904.7786842338604526772412943845 cubic inches
vbox-sphere=1728-904.7786842338604526772412943845=823.2213157661395473227587056155
space filled by packing beads is about 823.22 cubic inches
beads percent is 823.2213157661395473227587056155/1728 times 100=47.64% filled by beads