Help me plz. Thank you!

f(320)= how much Dereck pays for phone service if he calls  320 minutes.

F(320)=0.11(320)+43=35.2+43=78.2

the value of f(320) is $78.2 and it will be the cost of phone service for 320 minutes of international calls.  

Step-by-step explanation:

Let the width be x inches. And it is given that length is 1 more then the width, so length = (x+1)inches . And it is given that height is 1 more then the length , so height is (x+1+1) inches = (x+2) inches

THe formula of volume is

Volume = length times width times height .

Substituting the values of volume, length , width and height,we will get

847.875 = x(x+1)(x+2)

On multiplying the right side, we will get

Subtracting 847.875 to both sides

That gives x= 8.5

So the width =8.5 inches, length = 8.5+1 =9.5 inches and height =9.5+1 =10.5 inches .