Whats the difference between system and ecosystem

For 2018, rahal's auto parts estimates bad debt expense at 1% of credit sales. the company reported accounts receivable and an allowance for uncollectible accounts of $86,500 and $2,100, respectively, at december 31, 2017. during 2018, rahal's credit sales and collections were $404,000 and $408,000, respectively, and $2,340 in accounts receivable were written off.rahal's accounts receivable at december 31, 2018, are:

Suppose farmer lane grows and sells cotton in a perfectly competitive industry. the market price of cotton is $1.64 per kilogram, and his marginal cost of production is $1.44 per kilogram, which increases with output. assume farmer lane is currently earning a profit. can farmer lane do anything to increase his profit in the short run? farmer lane: a. cannot do anything to increase his profit. b. may or may not be able to increase his profit. c. can increase his profit by raising his price. d. can increase his profit by producing more output. e. can increase his profit by shutting down.

The market demand curve for a popular teen magazine is given by q = 80 - 10p where p is the magazine price in dollars per issue and q is the weekly magazine circulation in units of 10,000. if the circulation is 400,000 per week at the current price, what is the consumer surplus for a teen reader with maximum willingness to pay of $3 per issue?