Answer
1) The linear equation which relates daily cost C in dollars is given by$C(x)=8x+500$
2) For 400 pair of jeans the cost is $\$3700$
3) For 740 pair of jeans the cost is $\$6420$
Work Step by Step
The linear cost equation is given by
$$Cost = Variable \ Cost + Fixed \ Cost $$
Fixed Cost = $\$500$
Variable Cost = Cost per item $\times $ Number of items.
Let $x$ be the number of pairs of jeans.
So, the variable cost =$\$8x$
The cost equation is given by $C(x)=8x+500$
The cost of manufacturing $400$ pairs of jeans is
$C(400)=8(400)+500$
$=3200+500$
= $3700$
The cost of manufacturing 740 pairs of jeans is
$C(740)=8(740)+500$
$=5920+500$
$=6420$
