The manager of a furniture factory finds that it costs $3000 to manufacture 80 chairs in one day and $4800 to produce 280 chairs in one day. (a) Express the cost C (in dollars) as a function of the number of chairs x produced, assuming that it is linear. C

9514 1404 393

  C = 9x +2280

Step-by-step explanation:

The 2-point form of the equation for a line can be a place to start.

  y = (y2 -y1)/(x2 -x1)(x -x1) +y1

  C = (4800 -3000)/(280 -80)(x -80) +3000 . . . . . use given values

  C = 1800/200(x -80) +3000 . . . . simplify some

  C = 9x -720 +3000 . . . . eliminate parentheses

  C = 9x +2280

to find the total number of combinations, multiply the quantity of each item by each other:

2 pairs of shoes x 3 pairs of shorts = 6 different combinations.