Math Word Problems
posted by Lisa .
Citydog Screen Printers received two orders for a tshirt designed for a math symposium. The first order was for 40 shirts at a total cost of $295 and the second order was for an additional 80 shirts at a total cost of $565. Each order included a shipping and handling charge.
Then we have to writer a linear equation, for which I got: y27/4x+25. We also had to find the cost per tshirt, for which I got: $31.75. The last part I don't understand, however: fidn the shipping and handling charge.
If anyone could help, I would really appreciate it. Thanks in advance.
The second word problem is:
It costs Consolidated Cereals Corporation $1050 to produce 100 boxes of corn flakes and $1250 to produce 500 boxes. I found the cost function: c(x)=1/2x+1000 but don't know how to determine the fixed cost and the variable cost per box (mainly because I have no idea what those are.)
Once again, thanks in advance.

I don't agree with your solution to the first question.
Cost= m x+b
x is the cost per shirt, b is the handling charge
295=40m+b
565=80m+b
subtract the first equation from the second:
370=40x solve for m, the cost of each shirt. Then solve for b, put all that into y= mx+b
One the second question,
Cost= variable cost * n + Fixedcosts or
cost= n*v+F
1250=500v+f
1050=100v+f
subtract the second equation from the first
200=400v solve for v, and it is 1/2 dollar. Solve for f, the fixed cost, and it looks as if it is 1000 dollars. 
Thanks for your help, but my teacher wanted me to use pointslope form to solve the equations rather than subtracting one equation from the other. Do you know how to do that?