If the fixed cost is $4000, and 50 items costs $7000 to produce, what is the linear cost function?

Cost = Fixed + (variable x units)

In this case, you know what fixed is so you can insert that. You know what the total is. The difference is the variable. So that gives you total variable, which you can use to figure out the variable unit cost. The function itself needs to have the variable in it for the units, otherwise it's an answer and not an equation which can be used to solve for different production amounts.

So it would look something like (using made-up numbers):
C(x) = 10,000 + 40x
where x is the units.

You're using the information you have at a specific x in order to make the equation, which can then be used to solve for any x.

4000+7000x

4000+7000x

7000=4000+50x
7000-4000=50x
3000/50=x
x=60

7000=4000+50x
7000-4000=50x
3000/50=x
x=60

7000=4000+50x
7000-4000=50x
3000/50=x
x=60

Thread is from 2008...

TC=FC+VC*Q ,where-Tc total cost
FC fixed cost
VC variable cost
Q unit produced
7000=4000+vc(50)
7000-4000=VC*50
3000=VC*50
VC=3000/50
VC=60 ,so cost equation should be ;
TC=4000+60*VC

how to form price equation?