Final answer:
To perform a subtraction using external worksheet references, insert the formula ='[PB Financials.xlsx]Income Statement'!B5 - '[PB Expenses.xlsx]Expenses'!B9' in cell B7. Ensure that both the referenced workbooks are open or accessible for the formula to work.
Step-by-step explanation:
To create a formula in cell B7 on one worksheet that subtracts the value in cell B9 on the Expenses worksheet from the value in cell B5 on the Income Statement worksheet, you would typically write a formula that includes external references to another workbook. In this case, you need a formula that references cells from the PB Expenses.xlsx file and the PB Financials.xlsx file. Here's how you could structure the formula:
=Income Statement workbook's B5 cell value minus Expenses workbook's B9 cell value:
='[PB Financials.xlsx]Income Statement'!B5 - '[PB Expenses.xlsx]Expenses'!B9
Place this formula in cell B7 of the appropriate worksheet to perform the subtraction. Remember, for this formula to work, both the PB Financials.xlsx and PB Expenses.xlsx files must be open or the references must be valid and the files accessible.