Question

The cost (in dollars) of producing x units of a certain commodity is c(x)=5000+10x+0.05x^2

Find A=100 to x=105

so far i got

y-y/x-x= C(105)-C(100)/105-105

i don't understand how it comes out to be 101.25/5

please help me

Answer 1

You have not said what A is. You also introduce y without definition. You need to add parentheses to clarify your y-y/x-x equation.

Please restate the problem exactly as it was presented to you.

Answer 2

I appears that you are attempting to calculate the average rate of change of the cost as the number of units changes from 100 to 105

that rate would be [C(105)-C(100)]/[105-100]
which does work out to be 101.25/5

Answer 3

wait so whats is c(105) is it 5000+10x+0.05x^2 times 105?

Answer 4

It appears you are not familiar with the function notation.
In short
if C(x) = 5000+10x+0.05x^2
then C(105) = 5000 + 10(105) + .05(105)^2

(whenever an x appeared, we replaced it with 105, the same thing with C(100) )