Answer:

Step-by-step explanation:
We are given that a function

We have to find the average value of function on the given interval [1,e]
Average value of function on interval [a,b] is given by

Using the formula 

By Parts integration formula

u=ln x and v=dx
Apply by parts integration
![f_{avg}=\frac{1}{e-1}([xlnx]^{e}_{1}-\int_{1}^{e}(\frac{1}{x}\times xdx))](https://tex.z-dn.net/?f=f_%7Bavg%7D%3D%5Cfrac%7B1%7D%7Be-1%7D%28%5Bxlnx%5D%5E%7Be%7D_%7B1%7D-%5Cint_%7B1%7D%5E%7Be%7D%28%5Cfrac%7B1%7D%7Bx%7D%5Ctimes%20xdx%29%29)
![f_{avg}=\frac{1}{e-1}(elne-ln1-[x]^{e}_{1})](https://tex.z-dn.net/?f=f_%7Bavg%7D%3D%5Cfrac%7B1%7D%7Be-1%7D%28elne-ln1-%5Bx%5D%5E%7Be%7D_%7B1%7D%29)

By using property lne=1,ln 1=0

 
        
             
        
        
        
X-7=13
move -7 to the right side of the equation, change the sign from negative to positive when you move it
x-7+7=13+7
x=13+7
x=20
        
             
        
        
        
The correct answer to determine the change in he account is by:
C. Subtracting last Monday's account balance from this Monday's account balance to find that the change in the balance is -$24.10.
Hope This helped :)
        
             
        
        
        
Answer:
10+2x= the sum (anything could be put here)
Step-by-step explanation:
Well sum is automatically addition
Doubleing a number is basically multiplying it by 2 
so 
10+2x= whatever youw ant to put here