please help

Johnson Enterprises uses a computer to handle its sales invoices. Lately, business has been so good that it takes an extra 3 hours per night, plus every third Saturday, to keep up with the volume of sales invoices, Management is considering updating its computer with a faster model that would climinate all of the overtime processing. If sold now, the current machine would have a saiv3se value of $8,100. If operated for the remainder of its useful life, the current machine would have zero salvage value. The new machine is expected to have zero salvage value after 5 years. Prepare an incremental analysis to determine whether the current machine should be replaced. (in the first two columns, enter costs and expenses as positive amounts, end any amounts recelved as negotive amounts, In the third column, enter net income increases as positive. amounts and decreases as negative amounts. Enter negative amounts using elther a negative sign preceding the number es. 45 or parentheses es. (45)