Please only do requirement 4 thank you.

A note disclosed that the allowance for uncollectible accounts had a balance of $21 million and $45 million at the end of 2017 and 2016, respectively. Bad debt expense for 2017 was $42 million. Assume that all sales are made on a credit basis. Required: 1. What is the amount of gross (total) accounts receivable due from customers at the end 2017 and 2016 ? 2. What is the amount of bad debt write-offs during 2017 ? 3. Analyze changes in the following Accounts Receivable (gross) T-account to calculate the amount of cash received from customers during 2017. 4. Analyze changes in the following Accounts Receivable (net) T-account to calculate the amount of cash received from customers during 2017. Complete this question by entering your answers in the tabs below. Analyze changes in the following Accounts Receivable (net) T-account to calculate the amount of cash received from customers during 2017. (Enter your answers in millions.)